1st Corinthians 5:13

7 cleanse out, therefore, the old leaven, that ye may be a new lump, according as ye are unleavened, for also our passover for us was sacrificed -- Christ,

8 so that we may keep the feast, not with old leaven, nor with the leaven of evil and wickedness, but with unleavened food of sincerity and truth.

9 I did write to you in the epistle, not to keep company with whoremongers --

10 and not certainly with the whoremongers of this world, or with the covetous, or extortioners, or idolaters, seeing ye ought then to go forth out of the world --

11 and now, I did write to you not to keep company with [him], if any one, being named a brother, may be a whoremonger, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner -- with such a one not even to eat together;

12 for what have I also those without to judge? those within do ye not judge?

13 and those without God doth judge; and put ye away the evil from among yourselves.