Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved. Acts 4:12.
(LHU 324.1)
Adam, in his innocence, had enjoyed open communion with his Maker; but sin brought separation between God and man, and the atonement of Christ alone could span the abyss and make possible the communication of blessing or salvation from heaven to earth. Man was still cut off from direct approach to his Creator, but God would communicate with him through Christ and angels.
(LHU 324.2)
Thus were revealed to Adam important events in the history of mankind, from the time when the divine sentence was pronounced in Eden, to the Flood, and onward to the first advent of the Son of God. He was shown that while the sacrifice of Christ would be of sufficient value to save the whole world, many would choose a life of sin rather than of repentance and obedience. Crime would increase through successive generations, and the curse of sin would rest more and more heavily upon the human race, upon the beasts, and upon the earth. The days of man would be shortened by his own course of sin; he would deteriorate in physical stature and endurance and in moral and intellectual power, until the world would be filled with misery of every type. Through the indulgence of appetite and passion men would become incapable of appreciating the great truths of the plan of redemption. Yet Christ, true to the purpose for which He left heaven, would continue His interest in men, and still invite them to hide their weakness and deficiencies in Him. He would supply the needs of all who would come unto Him in faith. And there would ever be a few who would preserve the knowledge of God and would remain unsullied amid the prevailing iniquity.
(LHU 324.3)
The sacrificial offerings were ordained by God to be to man a perpetual reminder and a penitential acknowledgment of his sin and a confession of his faith in the promised Redeemer. They were intended to impress upon the fallen race the solemn truth that it was sin that caused death. To Adam, the offering of the first sacrifice was a most painful ceremony. His hand must be raised to take life, which only God could give. It was the first time he had ever witnessed death, and he knew that had he been obedient to God, there would have been no death of man or beast. As he slew the innocent victim, he trembled at the thought that his sin must shed the blood of the spotless Lamb of God.... And he marveled at the infinite goodness that would give such a ransom to save the guilty. A star of hope illumined the dark and terrible future and relieved it of its utter desolation....
(LHU 324.4)
The act of Christ in dying for the salvation of man would not only make heaven accessible to men, but before all the universe it would justify God and His Son in their dealing with the rebellion of Satan (Patriarchs and Prophets, 57-69).
(LHU 324.5)