The basics of my beliefs are... one man for one woman and once married, either can put each other away if they find out about previous things they didn't confess before marriage (fornication) or adultery during marriage.
They either forgive and forget and remain married, or they divorce and are NOT allowed to remarry just because they divorced.
If a couple have already divorced and remarried other people, they remain in that marriage once they come to the Truth - not make a mess of another marriage. They should not be doing that if they know the Truth - which is one husband for one wife.
As for abusive marriages, you can separate from them, remaining married.
Say you married someone who changed their beliefs later in life and wanted to divorce you because they didn't 'love' you anymore, I believe you need to pray about it but accept it as being God's will for your life - maybe temporarily. God can make that person love you again, change their mind, etc. Once divorced though, I don't think you can get back together. That seems like a harsh rule but it was because of the hardness of man's heart that they were made in the first place. You may get lonely and want someone else, but YOU made a vow and even if the other person doesn't honour it, YOU can. It seems harsh and cruel but must believe all things work together for good... I have seen many broken marriages and what Satan has done. It was never God's intention but He can make everything work out for our benefit. And He can fill any role that we need - for a widow/er, for someone single, for someone divorced or separated. (Of course widows and widowers can remarry but many choose not to)
That is why the choice of who you marry is so important because you are making a promise to them before God and should keep your word. If things happen so you cannot keep it, God is able to forgive but I wouldn't do things willfully ignorantly.
Somehow a lot of christians have overlooked any scriptures about divorce and marriage to justify moving from one partner to the next. That's because many preachers haven't told them the Truth. Some preachers are guilty of the same thing themselves. Now there are so many messes with marriages and divorce and remarrying because the Truth has been lost through the years. Only God can reveal it to people.
As for Mule's indication to eunuchs --- hehe Hey thats true! Some people can do it. Most get too lonely though and I guess that's why they want someone, even if they are going against God's will. People who can remain single and clean for their life are incredibly strong. Those who have had a husband or wife and then lose them for any reason and choose to honour their vow by never having the comfort of another like that - they have to be endued with strength from God and what a testimony!