Ben emailed me this explanation from his point of view on my post on predestined marriage:
You mentioned being a little confused about non-Christians choosing a mate. Just because we have a choice, doesn’t mean that we always choose what is best. A non-Christian still has the same choice a Christian does, and just because that choice can be made as a non Christian doesn’t mean the one chosen is any less “the one” for them. What it does mean is that they will almost certainly choose something that is less than what God would have arranged for them if they knew him. Remarkably, and somewhat paradoxically, this still doesn’t mean that what they chose is bad. God is able to redeem any situation, and if we turn to him with all our hearts, he will take our messed up decisions and somehow make them good (Romans 8:28). There are still consequences for our decisions, and it will be much more difficult for them than it could have been, but just because something is difficult doesn’t mean it isn’t the best. In non-Christian relationships the problem usually isn’t choosing the wrong mate, which to me seems like an oxymoron, but rather giving up because it’s difficult and then unchoosing. The stipulation you made at the end of your post “if you have a right standing with God and are in a place of prayer and clean conscience” is not a prerequisite for the concept to work, it just ensures the least heart ache in the process.