“And if you do not do well, sin is crouching at the door ...” (7). In this sin-darkened world, the new reality was that humans struggled against many temptations. Cain fell immediately into competition and envied his brother Abel, leading to murder (8). He could not “rule over” his own impulses, emotions, and desires, and his lack of control harmed his brother (7). Cain faced terrible consequences – banishment, estrangement - yet God also showed him extraordinary mercy (15). 

“At that time people began to call upon the name of the Lord” (26). Perfect fellowship with God and others had been broken, and sin “crouched at the door”, yet there was hope. Mercifully, God provides a way to deal with sin and calls us back to Himself.