Well, some of those who are single, are single for a good reason. I wouldn't invite anyone to marry some of these people. I have found some of these single people to be users, complainers, and failures. They just bring you down. Some of them.
Now the lesson in the Jerimiah book. I believe that the command given to Jerimiah 7, states that he wasn't to procure a wife, of have sons or daughters in this place. So what did Jeremiah do when he left Jerusalem? The Bible doesn't say. Jerimiah may have married in his old age. We don't know. Just like Paul, we don't know if he was married, yet, he advised against it. When I read the kind of man Paul was, I don't think I would feel comfortable in inviting him over, too.