There are 2 verses Mat 5:32 and Mat 19:3-9 that Jesus talked about divorce. In both he gave the exception clause. The example given was the man divorcing the wife. In those times, the wife is fully dependent on the husband for sustenance. Without a husband the divorced wife must necessarily remarry in order to survive. If the wife is chaste, the divorce will cause her to be an adulteress when she remarries in order to survive. Hence the guilt for the offending husband is more serious as he caused another to sin.
There may be OT biblical support for divorce. In Deuteronomy 24:4 the husband can not remarry a former wife because she has been “defiled” by another man. On that footing, one can argue that a cheating wife once defiled by another man, can not rejoin as one to her husband. So does that make divorce a permissible act in a cheating relationship?
God hates divorce Mal 2:16. To the extent that God continually overlook Israel’s , God’s OT bride , for being unfaithful. Jeremiah 3. I suspect the Church has taken the stance of forgiving and valuing the covenant with God on a higher level than the “defilement” part. There are a number of verses related to forgiveness. The one that comes to mind is if you don’t forgive others, we might not be forgiven either. Marriage is a holy covenant with God. 2 persons, joined as one, making the marriage vows in the presence of God. The man/woman team, even on bad terms with each other, still has a valid covenant with God. So only death ends this covenant. Or if all 3 parties agree which will not happen since God already declared he hates divorce.
But does Mat 5:32 actually permits divorce? If one slice and dice the language, it says if the wife is unchaste, then the husband will not be guilty of causing her to be an adulteress. But it does not say divorce is permissible for him, only that he is not guilty of causing his wife to be an adulteress because she already is. I can not identify from the language that Jesus is permitting divorce.
But I tell you that anyone who divorces his wife, except for sexual immorality [porneias], makes her the victim of adultery [moichatai], and anyone who marries a divorced woman commits adultery [moichatai]. (NIV)