In chapter 3 we read of man sinning against God by disobeying His Word; in chapter 4 we read of man sinning against man. James 1:15 warns us that sin begins in a small way, but grows and leads to death. And so it was with Cain. There was disappointment, anger, jealousy, and, finally, murder.
Both Cain and Abel brought offerings to God. While Abel brought a blood offering, which was acceptable to God, Cain brought a bloodless offering from the cursed earth. His offering may have been sincere, but it was not accepted.
We see in these verses the contrast between religion based on good works and self-righteousness, and the religion of grace which is through the blood of Jesus Christ. There are only two religions in the world today: that of Abel, that depends on the blood of Christ and His finished work on the cross; and that of Cain, that depends on good works and man-pleasing religious ceremonies and programs. Abel's religion leads to heaven; Cain's religion leads to hell.
Chapter 6 deals with the flood and the faith of Noah. The fact of the flood is proved by the Genesis record, as well as by Christ (Matthew 24:37-39 and Luke 17:26), the prophets (Isaiah 54:9), and the apostles (I Peter 3:20). Man had become corrupt, the earth was filled with violence, and God had to destroy mankind. There must always be judgment and death before there can be a new beginning.
The ark is a wonderful picture of our salvation in Christ. The ark not only saved mankind, but also the creatures within it, just as Christ's death will one day deliver creation from the bondage of sin. The ark saved Noah and his family from judgment; Christ saves us from the wrath to come. There was only one way of salvation and that was through the door of the ark. Today there is only one way of salvation, and that is through Christ. Just as Noah went out of the ark, the head of a new creation with his family, Christ came out of the tomb, the Head of a New Creation, and the Father of a new family.
