Malachi 3:6a-b and Hebrews 13:8 --- God does not change (nor would He, therefore, "tolerate" sin).

Titus 1:6 and 1 Timothy 3:2,12 --- "One wife" --- mia is the Greek word (for the word, one, in those passages) which is actually used for first as in "first day of the week" in Matthew 28:1, Mark 16:1-2, and Acts 20:7. Furthermore, in 1 Timothy 5:9, a widow's "one man" is not mia but the Greek word heis, meaning the numeral-one, and not meaning "first".

Exodus 21:10 protects the first (and previous) wife(s). Note that this verse comes only 22 verses AFTER the 7th Commandment against Adultery in Exodus 20:14.

Malachi 2:14-15 --- "wife of thy youth" is a man's first wife, the wife with whom he grew and learned how to so love, bless, and edify any wife.

1 Corinthians 7:27-28d is ONLY about married men (whether or not a previous wife has departed). If a man marries another wife, he and the new wife have not sinned.

1 Corinthians 7:10-11 is a Commandment of God that, when a previously-departed wife returns, her husband and his new wife (from verse 27c-28d) MUST let the previous wife be reconciled to her husband.

1 Kings 11:3-4: Solomon multiplied wives (up to 1,000!) which was prohibited and prophesied that a king would do in Deuteronomy 17:17. But that passage in 1 Kings 11:3-4 says his father David's heart was "perfect". Indeed, where Solomon had multiplied (i.e., stored-up, hoarded), David had only added his 18+ wives. (In Genesis 25:1, "Then AGAIN Abraham took a wife... Keturah". The word,"AGAIN", there translates to add --or "augment"-- in the Hebrew. And, indeed, Abraham was adding his third wife Keturah to himself.) So, Solomon's sin was muliplying wives while his father David had simply added wives.

Deuteronomy 21:15-17: this is a specific instruction in the Law Itself to any man with "two wives".

1 Corinthians 5:1: A son had fornicated with his "father's wife". This does NOT refer to the man's mother. Indeed, the term, "father's wife", is a very specific term. Leviticus 18:8 refers to "father's wife" as specifically separate from "mother" in the previous verse of Leviticus 18:7. Note that the "nakedness" of a "mother" is referred to as her own "nakedness" while the "nakedness" of a "father's wife" is referred to as the FATHER's "nakedness". This same differentiation is observed again in Deuteronomy 27:20,16. In fact, what the fornicator had done as per 1 Corinthians 5:1 was the same sin as that of Jacob/Israel's firstborn son. Reuben had committed the identical sin with Jacob/Israel's wife, Bilhah, in Genesis 35:22. (Yes, Bilhah was Jacob's wife ; see Genesis 37:2.) And for Reuben's act of "uncovering his father's nakedness" by fornicating with his "father's wife", Bilhah, Reuben lost his birthright as firstborn. 1 Chronicles 5:1 reveals that this was because Reuben had "defiled his father's bed". Indeed, the reference to "father's wife" in 1 Corinthians 5:1 does reveal an actual polygamist identified in the New Testament, i.e., the father of the mentioned fornicator. Matthew 19:8-9, Jesus simply repeats the Deuteronomy 24:1 "as it had been in the beginning" when it was written. In Matthew 19:3, the Pharisees were asking about "every" reason for divorcing, but Jesus returned back with the only one allowed reason (the woman's "fornication/uncleanness"), as per Deuteronomy 24:1 .

"ADULTERY" --- na`aph (pronounced: naw-af') in the Hebrew means, "WOMAN that breaketh wedlock". This applies to that same (as just above) Matthew 19:9 verse. Namely, note that (in that verse) it is because the first husband CAUSED his first wife to commit adultery (by violating Exodus 21:10, see above, in putting her away so as to "replace her") that he is therefore guilty of CAUSING her adultery. That is HOW he is guilty. He had CAUSED his first wife to "break her wedlock contract". And of course, that first wife for "breaking her wedlock contract" with her first husband, and the "second husband" for particiapting in that act, are both guilty too. But notice, the SECOND WIFE is not guilty of anything. And if the first husband had not put away his first wife, but instead kept her as well as marrying the second wife, he would not have CAUSED his first wife to "break her wedlock contract". Hence, he would not have been guilty of any Adultery in any way. Indeed, Adultery simply and only means "WOMAN that breaketh wedlock".

1 Timothy 4:1-3a: the "Spirit speaketh expressly" and prophesied of the time of "forbidding to marry".