'Unfaithfully' in the Bible

Have we not all one father? Hath not one God created us? Why do we deal unfaithfully every man against his brother, by profaning the covenant of our fathers?

Judah hath dealt unfaithfully, and an abomination is committed in Israel and in Jerusalem; for Judah hath profaned the sanctuary of Jehovah which he loved, and hath married the daughter of a strange god.

Yet ye say, Wherefore? Because Jehovah hath been a witness between thee and the wife of thy youth, against whom thou hast dealt unfaithfully: yet is she thy companion, and the wife of thy covenant.

And did not one make them? and the remnant of the Spirit was his. And wherefore the one? He sought a seed of God. Take heed then to your spirit, and let none deal unfaithfully against the wife of his youth,

(for I hate putting away, saith Jehovah the God of Israel;) and he covereth with violence his garment, saith Jehovah of hosts: take heed then to your spirit, that ye deal not unfaithfully.