Why did cain slew abel?
Cain killed Abel because of jealousy. This is well explained in this short article from the Insight on the Scriptures book. Read it carefully and look up the cited scriptures and you will see. Cain became a cultivator of the ground and, “at the expiration of some time,” he, as well as his younger brother Abel, brought offerings to present to Jehovah, feeling the need to gain God’s favor. Cain’s offering of “some fruits of the ground,” however, was not ‘looked upon with any favor’ by God. (Ge 4:2-5; compare Nu 16:15; Am 5:22.) While some point out that Cain’s offering is not said to be of the choicest fruits whereas Abel’s offering is specified to have been of the “firstlings of his flock, even their fatty pieces,” the problem was not in the quality of produce that Cain offered. As Hebrews 11:4 points out, Cain’s offering lacked the motivation of faith that made Abel’s sacrifice acceptable. The fact that God did not view Cain’s offering with favor may also have been because his offering
