1 John 4:20

4:20 If anyone says “I love God” and yet hates his fellow Christian, he is a liar, because the one who does not love his fellow Christian whom he has seen cannot love God whom he has not seen.

1 John 5:20

5:20 And we know that the Son of God has come and has given us insight to know him who is true, and we are in him who is true, in his Son Jesus Christ. This one is the true God and eternal life.