Let us now turn to the subject of truth as John deals with it in his first letter.
John’s concern about truth revolves around two main things:
(a) Antichrists, false teachers, have already arisen. "Even now many antichrists have arisen. From this we know it is the last hour" (1John 2:18; 4:5).
(b) False teachers were not genuine converts. "They went out from us but they were not really of us" (1John 2:19).
(c) The antichrist is not someone just honestly mistaken, teaching error out of ignorance. No, the antichrist's heart is as false as his teaching. "These things have I written to you concerning those who are trying to deceive" (1John 2:26).
(a) Truth was preached by inspiration of the Spirit. When we hear the gospel, it is a message that comes not from the world, but from the Holy One. "But you have an anointing from the Holy One, and you all know... the truth... you heard from the beginning" (1John 2:20-27).
(b) Error comes from the world, whilst truth comes from the scriptures. "They speak from the world and the world listens to them... he who knows God listens to us... By this we know the spirit of truth and the spirit of error" (1John 4:4-6).
(c) All truth is in Jesus Christ. "And we know that the Son of God has come and has given us understanding, in order that we might know him who is true, and we are in him who is true, in his Son Jesus Christ. This is the true God and eternal life" (1John 5:20).
(a) We must confess the truth, and not deny it, that Jesus is the Christ. "Who is a liar but the one who denies that Jesus is the Christ?" (1John 2:22-23).
(b) Another example is the truth that Jesus Christ has come in the flesh. "Every spirit who confesses that Jesus Christ has come in the flesh is from God" (1John 4:2-3). "And the Word became flesh and dwelt among us, and we beheld his glory, the glory as of the only begotten of the Father full of grace and truth" (John 1:14)
Truth should also be in our hearts and lives. "Let that abide in you which you heard from the beginning" (1John 2:24).
John says, "If what you heard from the beginning abides in you, you will also abide in the Son and in the Father" (1John 2:24). Note how John is not saying that the truth that abides in you should be constantly updated to the latest version. The truth that was preached from the beginning is the only truth. It does not change over time.
John exhorts us not to believe every teacher who claims to have a true spiritual message. Rather we should "test the spirits whether they be of God, because many false prophets have gone out into the world" (1John 4:1).
John describes Jesus as "the true God" and in the next dip of his pen closes his letter abruptly with this terse command: "Little children, guard yourselves from idols" (1John 5:20-21).
When we digress from the truth, we digress from the true God and put ourselves in danger of worshipping a god who is not true, a god created by human imagination.