I was involved in a long-distance relationship. A very serious one that I got engaged in,, eventually. Ultimately, God was not in it, and I ignored that. It thence failed miserably amd painfully by our inability to reconcile the diference between what we sold ourselves on and the truth. Fortunately, God kept it from getting to the point of marriage or children before it broke, but I still sinned because I disobeyed Him.
My advice would be that you must NOT go into a long distance relationship believing that you can get to know them reasonably with your time spent in long-distance contact, regardless of what that might entale. Long-distance relationships require even MORE time and careful consideration because you are getting to know the other's private character (or what they are willing to share of it) in fast-forward, while learning their public character (ie: with family, friends, and strangers) at a virtual stand-still. Both aspects are vital to getting to actually know a person. Usually the order of that is reversed (at least for what I see as healthier beginnings). It is possible to make it work, but not if it's basedon fantasy, and NEVER if it is serving anything but a desire to see the other person elevated in their relationship with Christ over their relationship with eachother. In this way, you guard your heart and theirs, and honor God in the process. Take things EXTREMELY slow and always under submission to Christ, and be sure you mutually understand that if God isn't in it, neither of you should be either. That applies to ALL relationships, though, frankly.