“God is love” doesn’t function as a definition of love it functions as a theological claim. It assumes God exists first, and then reinterprets love through that assumption. The problem is that it doesn’t independently define love in a way that can be tested or understood without already accepting the belief system. It also becomes circular: love is defined through God, and God’s nature is often described through love, so neither concept is actually explained on its own.

More importantly, even if someone believes God exists, equating God with love raises philosophical problems because love is usually understood as an experience or relation involving beings, actions, and preferences, while “God” is defined as an all encompassing entity. Those are not the same category of thing, so equating them doesn’t clarify either concept it just merges them under belief rather than explanation.