Little children, keep yourselves from idols (false gods)--[from anything and everything that would occupy the place in your heart due to God, from any sort of substitute for Him that would take first place in your life]. Amen (so let it be).
AMP
Little children, keep yourselves from idols. Amen.
KJV
Dear children, do not let anyone lead you astray. The one who does what is right is righteous, just as he is righteous.
NIV
Boys (lads), let no one deceive and lead you astray. He who practices righteousness [who is upright, conforming to the divine will in purpose, thought, and action, living a consistently conscientious life] is righteous, even as He is righteous.
AMP
Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.
KJV
But you, dear friends, by building yourselves up in your most holy faith and praying in the Holy Spirit
NIV
But you, beloved, build yourselves up [founded] on your most holy faith [make progress, rise like an edifice higher and higher], praying in the Holy Spirit
AMP
But ye, beloved, building up yourselves on your most holy faith, praying in the Holy Ghost,
KJV
Therefore, my dear friends, flee from idolatry.
NIV
Therefore, my dearly beloved, shun (keep clear away from, avoid by flight if need be) any sort of idolatry (of loving or venerating anything more than God).
AMP
Wherefore, my dearly beloved, flee from idolatry.
KJV
Dear friends, I am not writing you a new command but an old one, which you have had since the beginning. This old command is the message you have heard.
NIV
Beloved, I am writing you no new commandment, but an old commandment which you have had from the beginning; the old commandment is the message which you have heard [the doctrine of salvation through Christ].
AMP
Brethren, I write no new commandment unto you, but an old commandment which ye had from the beginning. The old commandment is the word which ye have heard from the beginning.
KJV
Therefore, dear friends, since you have been forewarned, be on your guard so that you may not be carried away by the error of the lawless and fall from your secure position.
NIV
Let me warn you therefore, beloved, that knowing these things beforehand, you should be on your guard, lest you be carried away by the error of lawless and wicked [persons and] fall from your own [present] firm condition [your own steadfastness of mind].
AMP
Ye therefore, beloved, seeing ye know these things before, beware lest ye also, being led away with the error of the wicked, fall from your own stedfastness.
KJV