Sin brought separation between God and the human family, and the atonement of Christ alone could span the abyss. God would communicate with people through Christ and angels. BOE 24.3
Adam was shown that while the sacrifice of Christ would be sufficient to save the whole world, many would choose a life of sin rather than of repentance and obedience. Crime would increase through later generations. The curse of sin would rest more and more heavily on the human race and the earth. The days of men and women would be shortened by their own course of sin; they would deteriorate in physical, moral, and intellectual power until the world would be filled with misery. Through the indulgence of appetite and passion, people would become incapable of appreciating the great truths of the plan of redemption. Yet Christ would supply the needs of all who would come to Him in faith, and there would always be a few who would preserve the knowledge of God and remain pure. BOE 24.4
The sacrificial offerings were given to show repentance for sin and to be a confession of faith in the promised Redeemer. The first sacrifice was painful for Adam. His hand must be lifted to take life, which only God could give. It was the first time he had witnessed death. He knew that if he had been obedient to God there would have been no death. He trembled at the thought that his sin must shed the blood of Christ, the spotless Lamb of God. This gave him a vivid sense of the greatness of his transgression, for which nothing but the death of God’s dear Son could atone. A star of hope illumined the dark future. BOE 24.5