Jesus said, divorce is only acceptable in cases of adultery. It's interesting because He goes further into it by saying, if you look at a woman to lust after her you have commited adultery in your heart.
Jesus was talking to the pharisee's and explaining the reasons Moses permited divorce was because of the heardness of their hearts.
What makes the looking and lusting so interesting is Jesus was basically showing that you should forgive adultery. Because, if you wife cheated, you also have cheated because you looked and lusted. You're both guilty. However, Jesus also realizes how hard (if not impossible for some) it would be to forgive something like this.
I believe it's also a double meaning in the sense of worshiping other gods and such.
Now, we can play games with this for a while such as. If you commit adultery, then you can legally get a divorce. If you divorce then remarry, you have commited adultery, so, since you commited adultery, your first divorce is valid in the eyes of God and that makes your second marriage okay.
Then we can say, well, since adultery is a sin, and I repented, then my second marriage is okay. Ultimately, you still didn't repent, because, that means either staying unmarried, or returning to your spouse. (in cases that don't involve adultery from the beginning.)
And the wheels go round and round.
Then we can take a look at 1 Corinthians 7:10
And to the married I command, yet not I, but the Lord, Let not the wife depart from her husband: 11But and if she depart, let her remain unmarried or be reconciled to her husband: and let not the husband put away his wife.
And, then later, about the unbelieving spouse. We're not in any form of binding marriage if we dont' wish to be with them. So, in the Lord, we can leave if we want, or if they want, they can leave. Then remarriage is okay, but, also, Later, or earlier (I can't find it at the moment.) The believer that was married to an unbeliever, must marry a believer if they remarry.
So, divorce just because you find yourself unhappy, is not okay. This is not an old covenant issue, this is also a new covenant issue.
From where I stand, we have some pretty clear cut guidelines for divorce and remarriage.
It's also pretty clear that, a believer that does this is bound by God, and therefore should have the knowledge in the forefront. A non believer is not bound by and law of God and therefore, if they become a believer their past is cleared and forgiven. Because at the time they didn't believe, they were not bound by anything. A believer on the other hand is bound because we have the wisdom and word of God in which we believe. Therefore, true repentence is required if one has been divorced and wants to remain a bishop.