Original Verse:
2nd Corinthians Chapter 12 Verse 21lest again when I come my God should humble me before you, and I should mourn for many of them that have sinned heretofore, and repented not of the uncleanness and fornication and lasciviousness which they committed.

Reference Verses:
2nd Corinthians Chapter 13 Verse 2I have said beforehand, and I do say beforehand, as when I was present the second time, so now, being absent, to them that have sinned heretofore, and to all the rest, that, if I come again, I will not spare;
1st Corinthians Chapter 6 Verse 9Or 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 men,
1st Corinthians Chapter 6 Verse 18Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body.
Galatians Chapter 5 Verse 19Now the works of the flesh are manifest, which are [these]: fornication, uncleanness, lasciviousness,
Colossians Chapter 3 Verse 5Put to death therefore your members which are upon the earth: fornication, uncleanness, passion, evil desire, and covetousness, which is idolatry;
2nd Corinthians Chapter 2 Verse 1But I determined this for myself, that I would not come again to you with sorrow.
2nd Corinthians Chapter 2 Verse 3And I wrote this very thing, lest, when I came, I should have sorrow from them of whom I ought to rejoice; having confidence in you all, that my joy is [the joy] of you all.