Book of III John~ I had many things to write

III John 1:13-14 (NKJV)

[13] I had many things to write, but I do not wish to write to you with pen and ink;
[14] but I hope to see you shortly, and we shall speak face to face.
Peace to you. Our friends greet you. Greet the friends by name.

Book of II John~ Beware of antichrist deceivers

II John 1:7-11 (NKJV)

[7] For many deceivers have gone out into the world who do not confess Jesus Christ as coming in the flesh. This is a deceiver and an antichrist.
[8] Look to yourselves, that we do not lose those things we worked for, but that we may receive a full reward.
[9] Whoever transgresses and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ has both the Father and the Son.
[10] If anyone comes to you and does not bring this doctrine, do not receive him into your house nor greet him;
[11] for he who greets him shares in his evil deeds.

Book of I John~ Do not love the things in the world

I John 2:15-17 (NKJV)

[15] Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him.
[16] For all that is in the world—the lust of the flesh, the lust of the eyes, and the pride of life—is not of the Father but is of the world.
[17] And the world is passing away, and the lust of it; but he who does the will of God abides forever.

Book of II Peter~ Deceptions of false teachers

2 Peter 2:18-2 (NKJV)

[18] For when they speak great swelling words of emptiness, they allure through the lusts of the flesh, through lewdness, the ones who have actually escaped from those who live in error.
[19] While they promise them liberty, they themselves are slaves of corruption; for by whom a person is overcome, by him also he is brought into bondage.
[20] For if, after they have escaped the pollutions of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in them and overcome, the latter end is worse for them than the beginning.
[21] For it would have been better for them not to have known the way of righteousness, than having known it, to turn from the holy commandment delivered to them.

Book of I Peter~ God resists the proud

I Peter 5:5-8 (NKJV)

[5] Likewise you younger people, submit yourselves to your elders. Yes, all of you be submissive to one another, and be clothed with humility, for “God resists the proud,
But gives grace to the humble.”
[6] Therefore humble yourselves under the mighty hand of God, that He may exalt you in due time,
[7] casting all your care upon Him, for He cares for you.
[8] Be sober, be vigilant; because your adversary the devil walks about like a roaring lion, seeking whom he may devour.