Well, I'm 65 and there's not much wonderful about by marriage but no, I don't think I've ever felt empty if by that you mean lonely or unfulfilled. I'm by nature very happy and optimistic and always have a ton of fun and/or interesting projects in the works.
Not sure what being non-Christian has to do with it. My beliefs would probably be called pagan but all organized religion repels me and always has. I suppose the kind of person who needed to be around people/family/community might feel odd with that outlook but I prefer, make that crave solitude, have no family (thank God and the gods!) and while I like my little remote, rural community I rarely participate in any of the social happenings aside from the occasional funeral to show respect.