1. The Aberration of divorce
18 “Everyone who divorces his wife and marries another commits adultery, and he who marries a woman divorced from her husband commits adultery. Luke 16:18 (ESV)

God views marriage as a covenant:

16 "For I hate divorce," says the LORD, the God of Israel Malachi 2:16 (NASB)

she is your companion and your wife by covenant. Malachi 2:14 (NASB)

2 For the married woman is bound by law to her husband while he is living; but if her husband dies, she is released from the law concerning the husband. Romans 7:2 (NASB)

Question:
7 They *said to Him, "Why then did Moses command to GIVE HER A CERTIFICATE OF DIVORCE AND SEND her AWAY?" 8 He *said to them, "Because of your hardness of heart Moses permitted you to divorce your wives; but from the beginning it has not been this way.
Matthew 19:7-8 (NASB)

1. The Abuse of divorce
31 "It was said, 'WHOEVER SENDS HIS WIFE AWAY, LET HIM GIVE HER A CERTIFICATE OF DIVORCE'; Matthew 5:31 (NASB)

3 Some Pharisees came to Jesus, testing Him and asking, "Is it lawful for a man to divorce his wife for any reason at all?" 4 And He answered and said, "Have you not read that He who created them from the beginning MADE THEM MALE AND FEMALE, 5 and said, 'FOR THIS REASON A MAN SHALL LEAVE HIS FATHER AND MOTHER AND BE JOINED TO HIS WIFE, AND THE TWO SHALL BECOME ONE FLESH'? 6 "So they are no longer two, but one flesh. What therefore God has joined together, let no man separate." Matthew 19:3-6 (NASB)

1 "When a man takes a wife and marries her, and it happens that she finds no favor in his eyes because he has found some indecency in her, and he writes her a certificate of divorce and puts it in her hand and sends her out from his house, 2 and she leaves his house and goes and becomes another man's wife, 3 and if the latter husband turns against her and writes her a certificate of divorce and puts it in her hand and sends her out of his house, or if the latter husband dies who took her to be his wife, 4 then her former husband who sent her away is not allowed to take her again to be his wife, since she has been defiled; for that is an abomination before the LORD, and you shall not bring sin on the land which the LORD your God gives you as an inheritance.
Deuteronomy 24:1-4 (NASB)

3. The Allowance of divorce
32 but I say to you that everyone who divorces his wife, except for the reason of unchastity, makes her commit adultery; and whoever marries a divorced woman commits adultery. Matthew 5:32 (NASB)

9 "And I say to you, whoever divorces his wife, except for immorality, and marries another woman commits adultery." Matthew 19:9 (NASB)

15 Yet if the unbelieving one leaves, let him leave; the brother or the sister is not under bondage in such cases, but God has called us to peace. 1 Corinthians 7:15 (NASB)

The allowance for divorce involves the circumstances of sexual infidelity and abandonment by an unbelieving spouse.