I am dating a girl from Israel, and considering becoming a Christian later via baptism. For practical reasons, if we do not get married, she will eventually have to go back to Israel. Therefore I am considering getting married in order to keep seeing each other, and then if we want to "really" get married, we will have a public wedding. And, if not, we can quietly divorce.
In Judaism, a marriage can be ended for a variety of reasons, as Hillel taught, or for sexual immorality only, as seems to be held by the school of Shammai. In the gospels, it seems that Jesus taught the latter view. Also, in the time of Jesus, polygamy was practiced among Jews (much to the chagrin of Romans who tried unsuccessfully to stamp it out for centuries) so it is likely that Jesus did not disapprove of having multiple wives (see for example https://www.biblegateway.com/passage/?search=Matthew+25) but only of divorce.
My question is how the Protestant churches approach divorce, in the case of a marriage where neither participant was baptized, and where there was no formal wedding ceremony, and only one witness. I have read that in the Catholic Church, a marriage between two non-baptized persons can be annulled via the http://en.wikipedia.org/wiki/Pauline_privilege . But Protestants do not consider baptism to be necessary at all. On the other hand they follow Paul quite a bit, so what do they mean by "unbelieving" partner. Both people are open minded and often times Protestants will admit that even the person themselves doesn't know if they are true believers or not. So, when it comes to divorce, what happens?
Add to that an additional problem. What if the non-Christian party wants to stay together, and the Christian party decides that they want to get divorced? What would Protestants say then? In short, how do they treat the teaching of Jesus on the matter? What do they do in practice when their faithful come to inquire about a divorce, and seek to get married again later?
I wish I didn't have to single out a particular denomination, as I am also curious about the views of the Orthodox church on this.