This is how we can be sure that we know him??y obeying his commands.

but whoever obeys his message really has the love of God in perfection in his heart. This is the way we can be sure that we are in union with him;

Children, it is the last hour. You have heard that Antichrist is coming, and many Antichrists have indeed appeared. So we may be sure that it is the last hour.

If you know that he is upright, you may be sure that everyone who acts uprightly is his child.

From that we can be sure that we are on the side of the truth, and satisfy our consciences in God's sight,

This is how we can be sure that we love the children of God: it is by loving God and obeying his commands.