1 John 3:10
3:10 By this the children of God and the children of the devil are revealed: Everyone who does not practice righteousness – the one who does not love his fellow Christian – is not of God.
1 John 3:24
3:24 And the person who keeps his commandments resides in God, and God in him. Now by this we know that God resides in us: by the Spirit he has given us.
1 John 4:9-10
4:9 By this the love of God is revealed in us: that God has sent his one and only Son into the world so that we may live through him.
4:10 In this is love: not that we have loved God, but that he loved us and sent his Son to be the atoning sacrifice for our sins.