By this we can be sure that we know Him -- if we practice obedience to His commands.

but whoever practices obedience to His message really has a perfect love of God in his heart. By this we can be sure that we are in union with Him:

No one who disowns the Son can have the Father. Whoever owns the Son has the Father too.

Anyone who keeps on hating his brother is a murderer; and you know that no murderer can have eternal life remaining in him.

But if anyone has the world's means of supporting life and sees his brother in need and closes his heart against him, how can love to God remain in him?

In this way you can recognize the Spirit of God: Every spiritual utterance which owns that Jesus Christ has come in human form comes from God,

and no spiritual utterance which disowns Jesus can come from God; it is the utterance of Antichrist. You have heard that it is coming, and right now it is already in the world.

By the fact that He has given us a portion of His Spirit we can be sure that we remain in union with Him and He in union with us.

This is how we can be sure that we love the children of God, by continuing to love God and to obey His commands.