A common question skeptic or disagreeable person would ask , Why did God wait four thousand years before sending His Son for a substitute to atone mankind for theirs sins, Why not send right after Adam and Eve fell into sin instead using animals, the ceremonial law, and the moral law throughout Old Testament?  Jesus needed a blueprint that came from God to authenticate who he was, for example, a builder needs a diagram or blueprint before he or she built a structure.  Jesus utters these words, “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them.  For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished.“ How was Jesus able to fulfil the Law and the prophets if there was not a plan to follow me Jesus needed a blueprint.  For example, the moral and ceremonial laws, along with the seven Jewish feasts, Passover, the Feast of Unleavened Bread, the Feast of First fruits, the Feast of Weeks, the Feast of Trumpets, the Day of Atonement, and the Feast of Tabernacles.

For instance, the Ten Commandments were declared by God Mount Sini. The Ceremonial Law was written by Moses found in the book of Leviticus third book of the Old Testament. 

Tim Keller wrote a piece called Old Testament Law and The Charge of Inconsistency. But even in the Old Testament, many writers hinted that the sacrifices and the temple worship regulations pointed forward to something beyond them. (cf. 1 Samuel 15:21-22; Psalm 50:12-15; Psalm 51:17; Hosea 6:6).

The moral and ceremonial laws are a fore shadow of Christ In when He will fulfill the moral and ceremonial laws and did away the ceremonial laws as scripture states, “Therefore it was necessary for the copies of the things in the heavens to be cleansed with these, but the heavenly things themselves with better sacrifices than these.“ Scripture declares “When the time came to completion, God sent His Son, born of a woman, born under the law, At the right time Christ died for the ungodly.”

https://www.redeemer.com/redeemer-report/article/old_testament_law_and_the_charge_of_inconsistency

 Throughout the Old Testament alter were built as means sacrificing the animals where the animals were slain, and blood was spilt as means atoning humankind for theirs sins. For example, an altar was built after flood, Genesis 8; 20- 21, “Then Noah built an altar to the Lord and, taking some of all the clean animals and clean birds, he sacrificed burnt offerings on it.  The Lord smelled the pleasing aroma and said in his heart: “Never again will I curse the ground because of humans, even though every inclination of the human heart is; evil from childhood. And never again will I destroy all living creatures, as I have done.

The seven Jewish feasts, Passover, the Feast of Unleavened Bread, the Feast of First fruits, the Feast of Weeks, the Feast of Trumpets, the Day of Atonement, and the Feast of Tabernacles. Jesus had to fulfil 

1) Passover (Leviticus 23:5) – Pointed to the Messiah as our Passover lamb (1 Corinthians 5:7) 

2) Unleavened Bread (Leviticus 23:6) – Pointed to the Messiah’s sinless life (as leaven is a picture of sin in the Bible), 

3) First Fruits (Leviticus 23:10) – Pointed to the Messiah’s resurrection as the first fruits of the righteous.  

4) Weeks or Pentecost (Leviticus 23:16) – Occurred fifty days after the beginning of the Feast of Unleavened Bread and pointed to the great harvest of souls and the gift of the Holy Spirit for both Jew and Gentile.

5) Trumpets (Leviticus 23:24) – The first of the fall feasts. Many believe this day points to the Rapture of the Church when the Messiah Jesus will appear in the heavens as He comes for His bride, the Church. The Rapture is always associated in Scripture with the blowing of a loud trumpet (1 Thessalonians 4:13-18 and 1 Corinthians 15:52).

6) Day of Atonement (Leviticus 23:27) – That will be the Day of Atonement for the Jewish remnant when they “look upon Him whom they have pierced,” repent of their sins, and receive Him as their Messiah (Zechariah 12:10 and Romans 11:1-6, 25-36).

7) Tabernacles or Booths (Leviticus 23:34) – Many scholars believe that this feast day points to the Lord’s promise that He will once again “tabernacle” with His people when He returns to reign over all the world (Micah 4:1-7).

https://www.gotquestions.org/Jewish-feasts.html 

The Old Testament prophets point to the Messiah was coming for in the seventy-week prophet found in Daniel 9; 20- 27 lay out great detail when the Messiah going dwell here on earth and when going to and rise again

Seventy weeks are determined upon your people and your Holy City to finish transgression, to put an end to sin, to atone for wickedness, to bring in everlasting righteousness, to seal up vision, and prophecy, 490 years later Jesus rode in with young colt into Jerusalem declares these words, “ “If you, even you, had only known on this day what would bring you peace–but now it is hidden from your eyes.  

After the sixty-two weeks, the Anointed One will be cut off The Hebrew word for Anointed One is Mashiach meaning Messiah. But in the middle of the week He will put a stop to sacrifice and offering.

Historical evidence is clear. Jesus began His ministry in27 AD and was crucified 3 ? Years later in 31 AD thus fulfilling the statement “in the midst of the week He shall cause the oblation and sacrifice to cease.” For centuries the Jews had slain the Passover lamb on Nisan 14, a Friday John the Baptist had declared in John 1:39 

“Behold the Lamb of God, which taketh away the sin of the world.”  When that Lamb was slain there was no longer a need for sacrifices and oblations.

Tim Keller wrote, ”But the reason is made clear. When he died on the cross the veil in the temple was ripped through, showing that the need for the entire sacrificial system with all its clean laws had been done away with. Jesus is the ultimate sacrifice for sin, and now Jesus makes us “clean.” NKJV commentary According to Grand Jeffrey in the book called  Armageddon: Appointment With Destiny the odds anyone fulfilling five prophecies centre around the messiah would been 120,00 to 1 for one person to accomplished.  It would like throwing a diamond ring in the middle of Atlantic Ocean and casting fishing line in the ocean and retrieving the diamond back in the first attempt. Never mind the over 300 prophesy on first and second coming written in the Old Testament about Him. “This would amount to 490 years before God’s people would experience perfect reconciliation with their God.”

Scholars or student of scripture has many views in how they understood the seventy prophecy. Where they do not doubt is Jesus is the Messiah, and the seventy-week prophecy was talking about the Messiah.     

The LORD said is declaring the end from the beginning, and from ancient times things not yet done, saying, ‘My counsel shall stand.” 

https://gracethrufaith.com/end-times-prophecy/the-70-weeks-of-daniel

http://www.bibleinfo.com/en/questions/70-week-prophecy-daniel 

Bottom line Jesus fulfilled the moral and ceremonial law and the Old Testament prophecies. His atoning work on the cross works 100%. When you repent, confess, believe and continue to believe