Abel was the son of Adam and Eve, the first people created by God. Although the Bible mentions Cain, his older brother, and Abel first, Mormon scripture reveals that Adam and Eve had many other children before these two were born. Cain’s fear that everyone would want to kill him, resulting in God giving him a mark to protect him, demonstrates that there must have been many people on the earth by the time he committed his crime.
Abel was the keeper of the sheep. He was a righteous man, far more so than his brother Cain. Abel received the priesthood from his father, Adam and bestowed it on Enoch.
“And she again bare his brother Abel. And Abel was a keeper of sheep, but Cain was a tiller of the ground. And in process of time it came to pass, that Cain brought of the fruit of the ground an offering unto the Lord. And Abel, he also brought of the firstlings of his flock and of the fat thereof. And the Lord had respect unto Abel and to his offering:” (See Genesis 4:2-4.)
Abel was killed by his brother Cain. They both took offerings to the Lord, but God rejected that of Cain’s because it was given in the wrong way for the wrong reason. Cain entered into a covenant with Satan and was taught to kill for personal gain. God reassured Cain that if he chose to live the gospel, his offerings would begin to be accepted, but instead Cain followed Satan’s teachings and killed Abel, possibly to gain control over the flocks.
Joseph Smith, the first Mormon prophet, used the experience of Cain and Abel’s sacrifices to help Mormons understand the nature of the atonement:
The symbols of the Lord’s sacrifice, in Adam’s day or our own, are to help us remember to live peacefully and obediently and mercifully. These ordinances are to help us remember to demonstrate the gospel of Jesus Christ in our long-suffering and human kindness one for another, as He demonstrated it for us on that cross.
But over the centuries, too few have used these ordinances in the proper way. Cain was the first to offer an unacceptable sacrifice. As the Prophet Joseph Smith noted: “Abel offered to God a sacrifice that was accepted, which was the firstlings of the flock. Cain offered of the fruit of the ground, and was not accepted, because he … could not exercise faith contrary to the plan of heaven. It must be shedding the blood of the Only Begotten to atone for man, for this was the plan of redemption, and without the shedding of blood was no remission. And as the sacrifice was instituted for a type by which man was to discern the great Sacrifice which God had prepared, to offer a sacrifice contrary to that, no faith could be exercised, because redemption was not purchased in that way, nor the power of atonement instituted after that order. … Certainly, the shedding of the blood of a beast could be beneficial to no man, except it was done in imitation, or as a type, or explanation of what was to be offered through the gift of God Himself.” (Teachings of Presidents of the Church: Joseph Smith [Melchizedek Priesthood and Relief Society course of study, 2007], 48.
Adapted from Every Person in the OT by Lynn F. Price; Horizon Publishers and the Bible Dictionary.