You can X-ray a soul pretty good over a fair period of time by seeing how they react to some pretty basic theological matters, not just as academic questions, but in how they live their lives. It requires paying attention, however. Something that many are not willing to do today.
If Christ is there today, Christ will also be there tomorrow.
I was widowed after 30 years of a good marriage. I dated a few women over the next dozen years, but either I decided I didn't want to marry them, or they didn't want to marry me. Finally I signed up with catholicsingles.com. I met a woman there, a widow. We spent several months chatting on line, at least an hour every morning. In six months there wasn't much we hadn't discussed. During that time we actually saw each other face to face only once, at an airport near me when she was changing planes while on her way to visit her son at college. Finally I flew to her place, hoping to find out of she was really like her on-line persona. Yes, she was. I proposed, and we've now had fourteen years of happy marriage. I attribute it all to the time we spent getting to know each other, even if it was via the Internet. There's no substitute for that. (Just remember, though, on the Internet no one knows you're a dog. You need to verify that the person on the other end really is as they present themselves.)