“Jude, a servant of Jesus Christ, and brother of James, to those who are called, sanctified by God the Father, and preserved in Jesus Christ: Mercy, peace, and love be multiplied to you. Beloved, while I was very diligent to write to you concerning our common salvation, I found it necessary to write to you exhorting you to contend earnestly for the faith which was once for all delivered to the saints. For certain men have crept in unnoticed, who long ago were marked out for this condemnation, ungodly men, who turn the grace of our God into licentiousness and deny the only Lord God and our Lord Jesus Christ.” Jude 1-4.
“But I want to remind you, though you once knew this, that the Lord, having saved the people out of the land of Egypt, afterward destroyed those who did not believe. And the angels [fallen angels, the, “sons of God” who may have had sex with women in Genesis 6: 1-4] who did not keep their proper domain, but left their own habitation, He has reserved in everlasting chains under darkness for the judgment of the great day; as Sodom and Gomorrah, and the cities around them in a similar manner to these, having given themselves over to sexual immorality and gone after strange flesh, are set forth as an example, suffering the vengeance of eternal fire.” Jude 5-7.
“Finally then, brethren, we urge and exhort in the Lord Jesus that you should abound more and more, just as you received from us how you ought to walk and to please God; for you know what commandments we gave you through the Lord Jesus. For this is the will of God, your sanctification: that you should abstain from sexual immorality…” 1 Thessalonians 4:1-3.
“Woe to her who is rebellious and polluted, to the oppressing city! She has not obeyed His voice, she has not received correction; she has not trusted in the Lord, she has not drawn near to her God. Her princes in her midst are roaring lions; her judges are evening wolves that leave not a bone till morning. Her prophets are insolent, treacherous people; her priests have polluted the sanctuary, they have done violence to the law.” Zephaniah 3:1-4.