Divorce is a big deal to the Christian faith, because it is breaking faith and unity

From Malachi 1:1-14,2:13-16 in the Office of Readings today:

And here is something else you do: you cover the altar of the Lord with tears, with weeping and wailing, because he now refuses to consider the offering or to accept it from your hands. And you ask, ‘Why?’ It is because the Lord stands as witness between you and the wife of your youth, the wife with whom you have broken faith, even though she was your partner and your wife by covenant. Did he not create a single being that has flesh and the breath of life? And what is this single being destined for? God-given offspring. Be careful for your own life, therefore, and do not break faith with the wife of your youth. For I hate divorce, says the Lord the God of Israel, and I hate people to parade their sins on their cloaks, says the Lord of Hosts. Respect your own life, therefore, and do not break faith like this.