Why do church people treat single people as outcasts?

Well, in my church there are several guys aged over 30 that have never married and are quite happy with their status as it stands. They aren't judged by other church members, many of whom are married with children. These guys are very productive and integral members of the church. They participate in every facet of everything the church does. While I am disappointed that your church is not like this, it is important to make the point that not every church group is hostile to singles. It is also counter productive to make a sweeping generalisation about an entire faith based on your experience with just one group. You will find people can be anti-single in all facets of society and not just one particular group who happens to be Adventist. Unfortunately people are not perfect, and they do make mistakes. I myself am single, and if any church member tried to take a shot at my marital status my response would be fairly direct and to the point - being single is my life choice and none of their affair. Deal with it.