The first two men who came to God to make an offering and worship are examples of the two ways that men have always came to God. Abel 's offering was accepted and Cain's was rejected. Most worship is of the kind that Cain offered and it is no more acceptable to God now than it was then. Abel worshipped the LORD God that created the heavens. Cain's idea of God was much lower. Evidently, his concept of God was just a better version of himself. He that worships God must worship Him in Spirit and in truth. Contemporary worship is generally focused on self, not on God, and that is not acceptable to God.