He that faith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.

I am writing to you fathers, because you have known Him [i.e., Christ], [who has existed] from the beginning [See John 1:1]. I am writing to you young men, because you have overcome the [power of the] evil one [i.e., through faith they had gained victory over Satan, See 5:4].

My little children, do not let our love be in word and in tongue, but let it be in act and in good faith.

This is His commandment, that we believe [with personal faith and confident trust] in the name of His Son Jesus Christ, and [that we unselfishly] love and seek the best for one another, just as He commanded us.

Beloved, do not believe every spirit [speaking through a self-proclaimed prophet]; instead test the spirits to see whether they are from God, because many false prophets and teachers have gone out into the world.

We have come to know [by personal observation and experience], and have believed [with deep, consistent faith] the love which God has for us. God is love, and the one who abides in love abides in God, and God abides continually in him.

Everyone who has faith that Jesus is the Christ is a child of God: and everyone who has love for the Father has love for his child.

For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.

Who is able to overcome the world but the man who has faith that Jesus is the Son of God?

The one who believes in the Son of God [who adheres to, trusts in, and relies confidently on Him as Savior] has the testimony within himself [because he can speak authoritatively about Christ from his own personal experience]. The one who does not believe God [in this way] has made Him [out to be] a liar, because he has not believed in the evidence that God has given regarding His Son.

I have put these things in writing for you who have faith in the name of the Son of God, so that you may be certain that you have eternal life.