That is an interesting idea. How many of you think that God creates people in pairs? I tend to think more that he just lets people be born naturally, and if there does happen to be anyone among the few billion people of a certain sex who is more suitable for a single person than all the others, then very well. Maybe I should make an analogy with food: I doubt that God puts just the right meal for me in the grocery store. I know that he designed the human body, and he also created all the plants and animals in the beginning, and if I really looked, I could probably find something in the grocery store that was particularly suitable for my body and physical state. If I prayed, God might even help me find the right one. However, again, I doubt that God actually puts an ideal or most suitable meal for me in the grocery store; there just happen to be lots of ingredients and prepared meals, and chances are that a few of them will be particularly suitable for me, just because they happen to be what's there. This is sort of how I think dating and marriage are. Of all the three billion or so people of the opposite sex, there probably is one out there who has higher mutual suitability with me than most or maybe even all, because she happened to be born to the right parents in the right environment, and she made the right choices (as far as I am concerned).
Nowadays, some people seem very concerned with this; we must marry the right one, not just anyone. In the ancient world, though, people just married the girl on the next farm, or their parents married them to other people because they were friends with the families. One could argue, of course, that in those times, the only suitable partner would be someone from the same community, who spoke the same language(s) and dialect(s), and had similar culture. On the other hand, maybe it doesn't really matter much, as long as the other person loves and serves God. Considering the divorce rates in cultures that tend to marry for 'love' instead of other reasons (such as family relations, political gain, et cetera), this seems sensible.