How do you ditch non-toxic friends?

I have two friends from a previous job I had. The problem I have is that we got along great as work colleagues, but personally I find them to be somewhat immature and irritating. They are what I refer to as ‘circumstantial friends’ – people you get along with in particular circumstances, like a workplace, but don’t share much in common outside of this. Normally, once you leave a job, you can just fade out of contact, but now, with the wonder of Facebook, they are still very much in contact with me.

I feel a bit callous, as they don’t seem to have many other friends, and they obviously value my friendship. They aren’t ‘toxic’ and have not done anything wrong. The issue is simply that, outside of work, we have very little in common, and have different outlooks on life and different values. They have a rather naive way of looking at things, and as I mentioned before, are somewhat immature. They remind me very much of being 16 again.

I’m getting married next year, and we’ll soon have to think about invitations. I don’t really want to invite them, as I would like our day to be filled with people who share our goals and values. I get the feeling, though, that they expect that they will be invited. Any suggestions on how we can divorce ‘circumstantial’ friends without hurting their feelings?