My advice: go ahead with the plan and meet the guy for coffee/lunch, but don't have sex. You seem uncertain about sex, so don't do it. But meet for coffee or what have you because you're interested enough to meet him and it's just the first meeting. You can always have sex later on with him, IF you choose to do so, but ONLY do it if you really want to and that's what you feel like doing. For now, I would just meet the guy, check him out, have conversation and see how you like him. See how you like him as someone you could have sex with.
IF you sense after the meeting that you could possibly really like this guy down the road, and IF you sense a real connection with him, then I would say be very very careful when proceeding because all he wants is sex, and you may want more. That's the tricky part of sex only relations... when one person may really like the other and wants more.
But you're not there yet, and haven't met him yet. He could be a total *** you never know. Even abusers seem nice in the beginning. Why is he separated? Do you know the backstory?
Anyways, for now meeting for coffee/lunch is innocent enough.
As for church, I really don't know what to advise. This is not a criticism whatsoever, but simply an observation. You seem to over commit or commit yourself, then not want to do whatever that commitment entails. Perhaps no commitments is better for you at this time, or very few and limited commitments? I don't really know.

Please don't take that the wrong way. You know I always hope and want the very best for you, whatever that is, and I am always rooting for you.

Just do what you feel is best for yourself. Always.
((((Hugs))))