1 Corinthians 7:15-20

15Yet if the unbelieving departeth, let him depart: the brother or the sister is not under bondage in such cases: but God hath called us in peace. 16For how knowest thou, O wife, whether thou shalt save thy husband? or how knowest thou, O husband, whether thou shalt save thy wife? 17Only, as the Lord hath distributed to each man, as God hath called each, so let him walk. And so ordain I in all the churches. 18Was any man called being circumcised? let him not become uncircumcised. Hath any been called in uncircumcision? let him not be circumcised. 19Circumcision is nothing, and uncircumcision is nothing; but the keeping of the commandments of God. 20Let each man abide in that calling wherein he was called.