God abides in people who confess that Jesus is the Messiah whose life, death, and resurrection are God's saving act for humanity is the Son of God, and they abide in God. This testifies to God’s love and to the fact that God is love.
The notion that God is love is one of the most important and influential teachings in 1 John. It follows from the metaphor God is light. We walk in the light when we abide in God by the power of the Spirit through faith in Jesus Christ, and in this way we love one another, love God, and properly love ourselves. This is how we know and walk in God, for God is love. Love for God and a proper love for self should lead us to love our sisters and brothers in Christ. Anyone who says “I love God” but hates his sisters and brothers is a liar.