'Fornicators' in the Bible

I wrote unto you in an epistle not to company with fornicators:

Yet not altogether with the fornicators of this world, or with the covetous, or extortioners, or with idolaters; for then must ye needs go out of the world.

Know ye not that the unrighteous shall not inherit the kingdom of God? Be not deceived: neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind,

Nor may we be fornicators, like some of them who committed fornication and on a single day 23,000 of them fell dead.