1 John 4:20 Updated American Standard Version (UASV)

20 If anyone says, “I love God,” and hates his brother, he is a liar; for he who does not love his brother whom he has seen cannot love God whom he has not seen.

“It is difficult to prove whether or not we love God based on our actions toward him because we cannot see him. Love for God is reflected in love for his children, our brothers and sisters, whom we can see. Therefore, God gave us this verifiable command: Whoever loves God must also love his brother. Jesus stated the principle in other words: whatever you did not do for one of the least of these you did not do for me (Matt. 25:40).” – David Walls and Max Anders