And no wonder! For Satan disguises himself as an angel of light. 2 Corinthians 11:14

4 Dear friends, do not believe every spirit, but test the spirits to deter
mine if they are from God, because many false prophets have gone out into the world. 2 This is how you know the Spirit of God: Every spirit who confesses that Jesus Christ has come in the flesh is from God. 3 But every spirit who does not confess Jesus[b] is not from God. This is the spirit of the antichrist; you have heard that he is coming, and he is already in the world now. 1 John 4; 1-3
24 False messiahs and false prophets will arise and perform great signs and wonders to lead astray, if possible, even the elect. 24 False messiahs and false prophets will arise and perform great signs and wonders to lead astray, if possible, even the elect.2 5 Take note: I have told you in advance. 26 So if they tell you, ‘Look, He’s in the wilderness!’ don’t go out; ‘Look, He’s in the inner rooms!’ do not believe it. Matthew 24; 24-26

John Calvin
Well Calvin live in the same era as Luther. they never met even thou they embrace same teaching as St. Augustine and believed the Roman Catholic Church was morality corrupt and were fleecing the poor instead feeding them.
John Calvin was born July 10, 1509 in Noyon, France and was brought was reared in a Roman Catholic family. His father wanted him to be priest, because of close ties with the bishop and his noble family. His friends and classmate were from a noble background and he was culturally influential in his early life. He moved to Orleans to study Civil law. Where he received Humanist education? His education was paid for partly by income from a couple of small parishes. Calvin was closely tied to the Roman Church.
However, in 1527 Calvin had developed friendships with individuals who was reform-minded. This contacts set the stage for Calvin’s eventual switch to the Reformed faith. Yet Calvin’s father advised him to study law instead of theology. During the autumn of 1533 Calvin experienced a religious conversion.
John Calvin wrote two accounts of his conversion that differed a significant way. In the first account he portrays his conversion as a sudden change of mind, brought about by God. In his second account he speaks of a long process of inner turmoil, followed by spiritual and psychological anguish. “Being exceedingly alarmed at the misery into which I had fallen, and more at that which threatened me in view of eternal death, I, duty bound, made it my first business to betake myself to God way, condemning my past life, not without groans and tears. And now, O Lord, what remains to a wretch like me, but instead of defence, earnestly to supplicate you not to judge that fearful abandonment of your Word according to its deserts, from which in your wondrous goodness you have at last delivered me?” He also wrote these words to the King Of France, “We, indeed, are perfectly conscious how poor and abject we are: in the presence of God we are miserable sinners, and in the sight of men most despised—we are (if you will) the mere dregs and off scourings of the world, or worse, if worse can be named: so that before God there remains nothing of which we can glory save only his mercy, by which, without any merit of our own, we are admitted to the hope of eternal salvation. because it is not ours, but that of the living God.”
He felt God was calling him to point out the abuses within the Catholic church and he was chosen instrument in the spiritual hectic regeneration of the world. He was highly critical of the abuses within the French Catholic churches .
Calvin broke with the Roman Church and was thrown in prison several times (for short stays) because of his evangelical activities. He became the head of the evangelical party in France less than a year after his conversion. However, like the Pharisee in Jesus time they treated the Protestant movement as a threat to the Roman Catholicism system. In a letter to the of King of France he penned these words,”My intention was only to furnish a kind of rudiments, by which those who feel some interest in religion might be trained to true godliness. And I toiled at the task chiefly for the sake of my countrymen the French, multitudes of whom I perceived to be hungering and thirsting after Christ, while very few seemed to have been duly imbued with even a slender knowledge of him. That this was the object which I had in view is apparent from the work itself, which is written in a simple and elementary form adapted for instruction.”
Calvin could have lost his life when he saw a fellow evangelical’s tongue cut out and the man burned at the stake. Calvin made a move towards the scaffold, but several other evangelicals dragged him away. Perhaps the words spoken by Jesus Christ inspire him “Blessed are you when people insult you and persecute you, and falsely say all kinds of evil against you because of Me. 12 Rejoice and be glad, for your reward in heaven is great; for in the same way they persecuted the prophets who were before you. He eventually went to Genova and established new church. His goal was preached and teach the atoning of Christ and declare the Roman Catholic false doctrine. Below is lists in which wrote against:

Monasteries were dissolved.
Mass was abolished .
Papal authority renounced.
There were to be no bishops. All ministers were equal.
The elders were civilian (laymen) who lived within the congregation.
The elders and deacons (also laymen who looked after the relief of the poor.
His commentaries, writing and Institutes of the Christian Religion are used in Christian schools to this day to equip future leaders.

In a letter to King of France he wrote these words,” Sire,—When I first engaged in this work, nothing was farther from my thoughts than to write what should afterwards be presented to your Majesty. My intention was only to furnish a kind of rudiments, by which those who feel some interest in religion might be trained to true godliness. And I toiled at the task chiefly for the sake of my countrymen the French, multitudes of whom I perceived to be hungering and thirsting after Christ, while very few seemed to have been duly imbued with even a slender knowledge of him. That this was the object which I had in view is apparent from the work itself, which is written in a simple and elementary form adapted for instruction.
But when I perceived that the fury of certain bad men had risen to such a height in your realm, that there was no place in it for sound doctrine, I thought it might be of service if I were in the same work both to give instruction to my countrymen, and also lay before your Majesty a Confession, from which you may learn what the doctrine is that so inflames the rage of those madmen who are this day, with fire and sword, troubling your kingdom. For I fear not to declare, that what I have here given may be regarded as a summary of the very doctrine which, they vociferate, ought to be punished with confiscation, exile, imprisonment, and flames, as well as exterminated by land and sea.
I am aware, indeed, how, in order to render our cause as hateful to your Majesty as possible, they have filled your ears and mind with atrocious insinuations; but you will be pleased, of your clemency, to reflect, that neither in word nor deed could there be any innocence, were it sufficient merely to accuse.
When any one, with the view of exciting prejudice, observes that this doctrine, of which I am endeavouring to give your Majesty an account, has been condemned by the suffrages of all the estates, and was long ago stabbed again and again by partial sentences of courts of law, he undoubtedly says nothing more than that it has sometimes been violently oppressed by the power and faction of adversaries, and sometimes fraudulently and insidiously overwhelmed by lies, cavils, and calumny. While a cause is unheard, it is violence to pass sanguinary sentences against it; it is fraud to charge it, contrary to its deserts, with sedition and mischief. That no one may suppose we are unjust in thus complaining, you yourself, most illustrious Sovereign, can bear us witness with what lying calumnies it is daily traduced in your presence, as aiming at nothing else than to wrest the sceptres of kings out of their hands, to overturn all tribunals and seats of justice, to subvert all order and government, to disturb the peace and quiet of society, to abolish all laws, destroy the distinctions of rank and property, and, in short, turn all things upside down. And yet, that which you hear is but the smallest portion of what is said; for among the common people are disseminated certain horrible insinuations—insinuations which, if well founded, would justify the whole world in condemning the doctrine with its authors to a thousand fires and gibbets. Who can wonder that the popular hatred is inflamed against it, when credit is given to those most iniquitous accusations? See, why all ranks unite with one accord in condemning our persons and our doctrine!Let it not be imagined that I am here framing my own private defence, with the view of obtaining a safe return to my native land. Though I cherish towards it the feelings which become me as a man, still, as matters now are, I can be absent from it without regret. The cause which I plead is the common cause of all the godly, and therefore the very cause of Christ—a cause which, throughout your realm, now lies, as it were, in despair, torn and trampled upon in all kinds of ways, and that more through the tyranny of certain Pharisees than any sanction from yourself. But it matters not to inquire how the thing is done; the fact that it is done cannot be denied. For so far have the wicked prevailed, that the truth of Christ, if not utterly routed and dispersed, lurks as if it were ignobly buried; while the poor Church, either wasted by cruel slaughter or driven into exile, or intimidated and terror-struck, scarcely ventures to breathe. Still her enemies press on with their wonted rage and fury over the ruins which they have made, strenuously assaulting the wall, which is already giving way. Meanwhile, no man comes forth to offer his protection against such furies. Any who would be thought most favourable to the truth, merely talk of pardoning the error and imprudence of ignorant men. For so those modest personages3 speak; giving the name of error and imprudence to that which they know to be the infallible truth of God, and of ignorant men to those whose intellect they see that Christ has not despised, seeing he has deigned to intrust them with the mysteries of his heavenly wisdom.Thus all are ashamed of the Gospel.
Your duty, most serene Prince, is, not to shut either your ears or mind against a cause involving such mighty interests as these: how the glory of God is to be maintained on the earth inviolate, how the truth of God is to preserve its dignity, how the kingdom of Christ is to continue amongst us compact and secure. The cause is worthy of your ear, worthy of your investigation, worthy of your throne.The characteristic of a true sovereign is, to acknowledge that, in the administration of his kingdom, he is a minister of God. He who does not make his reign subservient to the divine glory acts the part not of a king, but a robber. He, moreover, deceives himself who anticipates long prosperity to any kingdom which is not ruled by the sceptre of God, that is, by his divine word. For the heavenly oracle is infallible which has declared, that “where there is no vision the people perish”
Let not a contemptuous idea of our insignificance dissuade you from the investigation of this cause. We, indeed, are perfectly conscious how poor and abject we are: in the presence of God we are miserable sinners, and in the sight of men most despised—we are (if you will) the mere dregs and off scourings of the world, or worse, if worse can be named: so that before God there remains nothing of which we can glory save only his mercy, by which, without any merit of our own, we are admitted to the hope of eternal salvation: and before men not even this much remains, since we can glory only in our infirmity, a thing which, in the estimation of men, it is the greatest ignominy even tacitly to confess. But our doctrine must stand sublime above all the glory of the world, and invincible by all its power, because it is not ours, but that of the living God and his Anointed, whom the Father has appointed King, that he may rule from sea to sea, and from the rivers even to the ends of the earth; and so rule as to smite the whole earth and its strength of iron and brass, its splendour of gold and silver, with the mere rod of his mouth, and break them in pieces like a potter’s vessel; according to the magnificent predictions of the prophets respecting his kingdom.
Most illustrious King, may the Lord, the King of kings, establish your throne in righteousness, and your sceptre in equity.
Basle, 1st August 1536.
John Calvin illness;
Constant headaches which hardly ever left him.
Rachea which, when he spoke too much, caused him to spit blood.
Pleurisy prepared the way for consumption, of which he finally died.
Acute hemorrhoids, the pain of which was unbearably increased by an internal abscess that would not heal.
Intermittent fever laid him low, sapping his strength.
Gallstones and kidney stones in addition to stomach cramps and wicked intestinal influenza.

Even Calvin was abuse, and suffered and threaten throughout his life here’re some example, “He could not walk across the street without being mocked, ‘There he goes, neighbor. I prefer to hear three dogs barking than to listen to him preach.’ ‘Did you know, hell has only two devils, and there goes one of them!’ Children called after him, twisting his name, ‘Cain, Cain!’ More than one dog answered to the name.” Another incident, “ A wife of a leading stateman in Geneva was disciplined for dancing at a wedding. In response, she called Calvin a “pig” and a “lowdown liar.”

Calvin was an incessant worker who was always doing something for his master Jesus Christ. He wrote The Institutes and commentaries on almost every book of the Bible. He wrote other works and carried out prolific correspondence with most of the prominent Reformers in Europe and England. Calvin was the chief administrator for the church at Geneva, and he carried out his pastoral responsibilities with great care and concern. He rarely refused anyone counsel if it was a serious need. Calvin also preached or taught twice a day, and three times on Sunday.

Calvin Quotes
“We should ask God to increase our hope when it is small, awaken it when it is dormant, confirm it when it is wavering, strengthen it when it is weak, and raise it up when it is overthrown.”

“The torture of a bad conscience is the hell of a living soul.”

“There is no worse screen to block out the Spirit than confidence in our own intelligence.”

However many blessings we expect from God, His infinite liberality will always exceed all our wishes and our thoughts.

While John Calvin endured a lot throughout his life. Yet he shape people thinking, schools were name after him, and embraced his teaching,  Christian denominations adopted his doctrines, and many countries benefit from his teaching such as Scotland, Holland Canada, and USA. Yet he w as a simple believe In Jesus Christ and Him crucified. He preached it and was determined understand it. In short he was a servant of Christ. Dr. Jack L. Arnold wrote, “Whether a person agrees or disagrees with all of Calvin’s theology, every Protestant is indebted to this man. Lord, give us some more Calvins! “ or words written by the apostle Paul I have suffered the loss of all things and count them but dung, that I may win Christ.” There is a costs in preaching and teaching the gospel many follower of Christ throughout the ages were martyred because they were witness and testify atoning work and forgiveness of sins.The Greek words for witness is
martureó: to bear witness, testify.

John MacArthur once said that he studies dead guys Christian commentary instead of presence day commentary. Maybe their depth of thinking on the atoning work of Christ and God’s Word is useful for him when teaching the saints at Grace To You. Maybe it’s the shallow teaching in most of the commentary of this age that does not provide the depth when you equipping the saints within local church or they were willing to put their on the line.
The criticism I’ve many churches today is worship style as MacArthur calls it seven eleven style of worship that keeps repeating same seven words over and over again. That goes on for hours and very little time in teaching God’s words. Perhaps the words the Apostle Paul wrote count them but dung how see most style of worship today.
Throughout Reformation and the Puritan era They preached for hours it felt essential in equipping the masses and believed they were yearning for God’s words. For example Calvin taught, twice a day, and three times on Sunday. The masses in this day and age complains if the sermons are over thirty minutes long. Except for cases like Dr. Charles Stanley, Dr. John MacAuthor and Mike Bickle that preached sermon for over hours. My opinion if need to be somewhere than go why should those who hunger and thirst after God’s Word should suffer because you’re in hurry to go nowhere Perhaps the Apostle Paul long sermon in Acts 20; 9 illustrate my point. Yet still there’re some who are longing to dig deeper to God’s Words or in short getting into meat potato his words. Learning God’s word help to detect bad teaching and prevent them getting their meat hook into you, and exposing their false teaching.
There is a costs in preaching and teaching the gospel many follower of Christ throughout the ages were martyred because they were witness and testify atoning work and forgiveness of sin.The Greek words for witness is martureó: to bear witness, testify.