Since Adam and Eve fell into sin where Eve was deceived by Satan and Adam listened to his wife, and they ate the forbidden fruit. Than God pronounce a curse on Adam and Eve than He slew an animal and uses the skin to cover their bodies to cover their sins and It was means of covering up their private parts since lust entered the picture. As well as atoning both Adam and Eve sin. The skin was means of shielding their sin from God God’s eyes since He detested sin. As well atoning Adam and Eve sins where blood was required to atone Adam and Eve from their sins.
Did the animal deserve to be slain because of theirs sins? Of course not! Adam and Eve committed the terrible deed the animal kingdom where now part of the curse.
Than why were they sacrifice because someone else’s sinful acts? Because God was holy and righteous and loathes sin and require who committed no sin take humankind. As scripture declares, .” He made the One who did not know sin to be sin [for us. “
Another example found in Genesis 22; 1-19 where Abraham was about to sacrifice his only son Isaac until the LORD told to stop him and” provided a Ram in the bush it was substitute. As Believer Bible Commentary stated, “The ram is the second: an innocent victim died as a substitute for another, its blood was shed, and it was a burnt offering wholly consumed for God. It simply took Isaac place. Because of theirs sins, the animal took their place. Because of theirs disobedience the animal kingdom they once had dominion over was used to atone for their sins, As scriptures, “ Rule the fish of the sea, the birds of the sky, and every creature that crawls on the earth.” Four thousand later God sent his only Son to take sinful mankind place, in short He sent Himself to atone mankind sins.
Why did God wait four thousand years before send only Son a substitute and atone mankind sins, Why not send right after Adam and Eve fell into sin instead using animals, 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. “ Jesus needed a blueprint for example, the moral and ceremonial laws, along with 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.
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. When Abraham lied twice to two kings and said his wife Sarah was her sister he built an altar as means to atone for his lying and called upon the Lord found In Genesis 13; 4.
According to Bible history on Old Testament alters were build with stone without tools as describes.” In the earliest times of the Bible altars were made of earth or stones found in a field, and no tool could be used. They could not have steps lest the nakedness of man be exposed without a covering. They served as a table to place the sacrifice upon, and also to catch the blood of the sacrificial victim. In ancient Israel there were altars made of stone, and later a bronze altar was placed in the tabernacle of Moses. When Solomon became king he built a temple to the Lord in Jerusalem, and he created elaborate altars of bronze and gold. The animals were placed on the bronze altar, as a whole or in parts, bread was also place there, and meal, incense, and even wine was also offered. The Bible describes the most sacred part of the altar; these were the four horns on the corners which symbolized God’s power and might which pointed to the four corners of the earth (Exodus 27:2). God was clear that his salvation is for everyone, providing that they approach His way. When Cain brought the best of his good works on an altar he was rejected, while his sinful brother only brought a blood sacrifice, God accepted Abel’s sacrifice.” According to Exodus 20; 25 If you make a stone altar for Me, you must not build it out of cut stones. If you use your chisel on it, you will defile it.