Expositor's Bible Commentary Commentary 1 John 4:8

"He that loveth not knoweth not God; for God is love." — 1 John 4:8 (ASV)

Conversely, whoever does not love does not “know” God at all, for God in his very nature is love. To the statements, then, that God is light (1:5) and God is righteous (2:29), John adds the supreme statement “God is love [GK 27]” (4:8, 16). Love here is not to be understood as one of God’s many activities; rather, every activity of his is loving activity. Since this is true of God, our failure to love can only mean that we have no true knowledge of God, we have not really been born of him, and we do not have his nature.