World Wide Study Bible
a Bible passage
8. knoweth not—Greek aorist: not only knoweth not now, but never knew, has not once for all known God.
God is love—There is no Greek article to love, but to God; therefore we cannot translate, Love is God. God is fundamentally and essentially LOVE: not merely is loving, for then John's argument would not stand; for the conclusion from the premises then would be this, This man is not loving: God is loving; therefore he knoweth not God IN SO FAR AS God is loving; still he might know Him in His other attributes. But when we take love as God's essence, the argument is sound: This man doth not love, and therefore knows not love: God is essentially love, therefore he knows not God.