"And this is His commandment, that we believe in the name of His Son Jesus Christ, and love one another, just as He commanded us.  And the one who keeps His commandments abides in Him, and He in him.  And we know by this that He abides in us, by the Spirit whom He has given us."

You see the commandments of God boiled down to bare bones.  John wants us to be perfectly clear:  Faith and Love are what it is all about.

The way we love our brother, neighbor, one another... is of utmost importance to John as he writes.  Here, we see the reason that is so important to John.

John wants us to have faith; to believe in Jesus.

And verse 24 tells us of the reward.  He will abide in us and we will abide in Him.

In every relationship, belief is foundational.  We must believe that our friend likes us when he says he does, otherwise, haw can relationship happen?  Thus we see God's motive.  He wants us to believe in Him so we can be in relationship.

If you seek righteousness - seek faith.