1st John 3:15. “Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him.” MAN-MURDERER. It started with the devil; he was a murderer from the beginning. He wasn’t actually stained with blood, but deceived Eve into sinning. Adam made his choice and because of the devil, both did die. He did his murder by proxy, and his payday comes bye and bye.
Cain did not have life eternal, and he made a fatal decision. He rejected God offer of grace and for murder was never forgiven. His anger against God was such he from the Lord turned away, His murderous heart is a witness, to those who from God will stray.
Hatred of a brother is murder, the Lord Jesus clearly taught us that. Though you might never shed a person’s blood, murder is in the heart. The malice and evil that attends hatred before a murder is done, Is the same to God as if you had already killed someone.
A man-murderer is morally the same as one who hates his brother. To awaken man's conscience to God, Jesus said one is the same as the other. Anyone who continues like this and whose heart is black as the night, Certainly, does not possess the blessings of eternal life.
“Holy God, be merciful to those who have borne such hatred and by the light of the Gospel, bring them to repentance of this awful sin and to faith in the One who died for their sin. In the name of the Lord Jesus Christ, Amen.”