The Lord passed by before him, and proclaimed, The Lord, The Lord God, merciful and gracious, long-suffering, and abundant in goodness and truth, keeping mercy for thousands, forgiving iniquity and transgression and sin. Exodus 34:6, 7.
How grateful we should be that the Lord is slow to anger! What a wonderful thought it is, that Omnipotence puts a restraint upon His mighty power! But because the Lord is forbearing and long-suffering, the human heart often manifests a tendency to venture presumptuously to add sin to sin! ... “Because sentence against an evil work is not executed speedily, therefore the heart of the sons of men is fully set in them to do evil” (Ecclesiastes 8:11). Instead of God’s patience hardening the sinner to continual transgression, it should lead him to determine to seek God’s forgiveness, in order that the figures standing against his account in the heavenly record may be canceled...
Satan is the originator of evil. He swerved from his allegiance to God. Those who persisted in sympathizing with him in his disaffection were, with him, shut out of heaven. Implacable hatred against God fills Satan’s mind. Persistently he has used his influence to efface from the human family God’s image, and in its place to stamp his own satanic image. His effort to deceive our first parents was successful. Made in the image of God, the human family lost their innocence, became transgressors, and as disloyal subjects began their downward career. Satan gained control of man’s power of action. Through the senses he influenced the mind.
Thus it has been from the beginning of the world. Instead of remaining under God’s influence, in order that he might reflect the moral image of his Creator, man placed himself under the control of Satan’s influence and was made selfish. Thus sin became a universal evil. And what a dreadful evil is sin!
Yielding to Satan’s suggestions, our first parents opened the floodgates of evil upon the world. The questionable principles of the father and the mother of the human race influenced some of those with whom they associated. The evil that began in Paradise has extended down through the ages. Although Adam and Eve related with sorrow to their children the sad story of the Fall, their family became a divided family. Cain chose to serve Satan, Abel to serve God. Cain killed his brother Abel, because he would not follow his example.
That the world might not be destroyed because of its moral pollution, God undertook His great work of salvation, sending His Son to this earth to redeem mankind.—Manuscript 55, January 27, 1902, “The Long-Sufferance of God.”
Reference: E.G. White, "The Upward Look," p. 41