Jude 1:4

For there are certain craftily crept in, of which it was written aforetime unto such judgement. They are ungodly, and turn the grace of our Lord God unto wantonness; And deny God the only Lord, and our Lord Jesus Christ.

Galatians 2:4

and that because of incomers, being false brethren, which came in among others to spy out our liberty which we have in Christ Jesus, that they might bring us into bondage.

1 Peter 2:8

and a stone to stumble at, and a rock to offend them which stumble at the word, and believe not that whereon they were set.

1 John 2:22

Who is a liar, but he that denieth that Jesus is Christ? The same is the antichrist that denieth the father and the son.

2 Timothy 3:6

For of this sort are they which enter into houses, and bring into bondage women laden with sin, which women are led of divers lusts,

2 Samuel 22:5

For the waves of death have closed me about, and the floods of Belial have feared me.

Psalm 1:1

O Blessed is the man that hath not walked in the counsel of the ungodly, nor stood in the way of sinners, and hath not sat in the seat of the scornful.

Psalm 62:2

He only is my strength, my salvation, my defense, so that I shall not greatly fall.

Matthew 13:25

But while men slept, there came his foe, and sowed tares among the wheat, and went his way.

John 17:3

This is life eternal: that they might know thee, that only very God, and whom thou hast sent, Jesus Christ.

Acts 11:23

Which when he was come, and had seen the grace of God, was glad: and exhorted them all, that with purpose of heart they would continually cleave unto the Lord.

Acts 15:24

Forasmuch as we have heard that certain which departed from us, have troubled you with words, and cumbered your minds saying ye must be circumcised and keep the law: to whom we gave no such commandment.

Romans 6:1-2

What shall we say then? Shall we continue in sin, that there may be abundance of grace?

Romans 9:21-22

Hath not the potter power over the clay, even of the same lump to make one vessel unto honour, and another unto dishonour?

Galatians 5:13

Brethren, ye were called into liberty, only let not your liberty be an occasion unto the flesh but in love serve one another.

Ephesians 4:14

That we henceforth be no more children, wavering and carried with every wind of doctrine, by the wiliness of men and craftiness, whereby they lay a wait for us to deceive us.

1 Timothy 6:15-16

which appearing, when the time is come, he shall show that is blessed and mighty only, King of Kings, and Lord of lords,

Titus 1:15-16

Unto the pure, are all things pure: but unto them that are defiled, and unbelieving, is nothing pure: but even the very minds and consciences of them are defiled.

Titus 2:11-12

For the grace of God, that bringeth salvation unto all men, hath appeared

Hebrews 12:15-16

And look to, that no man be destitute of the grace of God, and that no root of bitterness spring up and trouble; and thereby many be defiled:

1 Peter 2:16

as free, and not as having the liberty for a cloak of maliciousness: but even as the servants of God.

1 Peter 4:18

And if the righteous scarcely be saved: where shall the ungodly and the sinner appear?

2 Peter 2:1-3

There were false prophets among the people, even as there shall be false teachers among you: which privily shall bring in damnable sects, even denying the Lord that hath bought them, and bring upon themselves swift damnation.

2 Peter 2:5-6

neither spared the old world, but saved Noah, the eighth preacher of righteousness, and brought in the flood upon the world of the ungodly;

2 Peter 2:10

namely, them that walk after the flesh in the lust of uncleanness, and despise the rulers. Presumptuous are they, and stubborn, and fear not to speak evil of them that are in authority;

2 Peter 2:18-22

For when they have spoken the swelling words of vanity, they beguile with wantonness through the lusts of the flesh them that were clean escaped: but now are wrapped in errors.

2 Peter 3:7

But the heavens verily and earth which are now, are kept by the same word in store, and reserved unto fire, against the day of judgment and perdition of ungodly men.

Jude 1:15

to give judgment against all men, and to rebuke all that are ungodly among them, of all their ungodly deeds, which they have ungodly committed, and of all their cruel speakings, which ungodly sinners have spoken against him."

Revelation 15:4

Who shall not fear, o Lord, and glorify thy name? For thou only art holy, and all gentiles shall come and worship before thee, for thy judgments are made manifest."

Treasury of Scripture Knowledge

Summary

For there are certain men crept in unawares, who were before of old ordained to this condemnation, ungodly men, turning the grace of our God into lasciviousness, and denying the only Lord God, and our Lord Jesus Christ.

Bible References

Crept

Matthew 13:25
But while men slept, there came his foe, and sowed tares among the wheat, and went his way.
Acts 15:24
Forasmuch as we have heard that certain which departed from us, have troubled you with words, and cumbered your minds saying ye must be circumcised and keep the law: to whom we gave no such commandment.
Galatians 2:4
and that because of incomers, being false brethren, which came in among others to spy out our liberty which we have in Christ Jesus, that they might bring us into bondage.
Ephesians 4:14
That we henceforth be no more children, wavering and carried with every wind of doctrine, by the wiliness of men and craftiness, whereby they lay a wait for us to deceive us.
2 Timothy 3:6
For of this sort are they which enter into houses, and bring into bondage women laden with sin, which women are led of divers lusts,
2 Peter 2:1
There were false prophets among the people, even as there shall be false teachers among you: which privily shall bring in damnable sects, even denying the Lord that hath bought them, and bring upon themselves swift damnation.

Who

Romans 9:21
Hath not the potter power over the clay, even of the same lump to make one vessel unto honour, and another unto dishonour?
1 Peter 2:8
and a stone to stumble at, and a rock to offend them which stumble at the word, and believe not that whereon they were set.
2 Peter 2:3
and through covetousness shall they with feigned words make merchandise of you, whose judgment is not far off, and their damnation sleepeth not.

Turning

Romans 6:1
What shall we say then? Shall we continue in sin, that there may be abundance of grace?
Galatians 5:13
Brethren, ye were called into liberty, only let not your liberty be an occasion unto the flesh but in love serve one another.
Titus 2:11
For the grace of God, that bringeth salvation unto all men, hath appeared
Hebrews 12:15
And look to, that no man be destitute of the grace of God, and that no root of bitterness spring up and trouble; and thereby many be defiled:
1 Peter 2:16
as free, and not as having the liberty for a cloak of maliciousness: but even as the servants of God.
2 Peter 2:10
namely, them that walk after the flesh in the lust of uncleanness, and despise the rulers. Presumptuous are they, and stubborn, and fear not to speak evil of them that are in authority;

Denying

Titus 1:15
Unto the pure, are all things pure: but unto them that are defiled, and unbelieving, is nothing pure: but even the very minds and consciences of them are defiled.
2 Peter 2:1
There were false prophets among the people, even as there shall be false teachers among you: which privily shall bring in damnable sects, even denying the Lord that hath bought them, and bring upon themselves swift damnation.
1 John 2:22
Who is a liar, but he that denieth that Jesus is Christ? The same is the antichrist that denieth the father and the son.

General references

Leviticus 15:8
If any such spit upon him that is clean, he must wash his clothes and bathe himself in water and be unclean until even.
Matthew 24:11
And many false prophets shall arise, and shall deceive many.
1 Timothy 5:15
For many of them are all ready turned back, and are gone after Satan.
James 2:19
Believest thou that there is one God? Thou doest well. The devils also believe and tremble.