Like moths to light.

I think that people that are in religions, primarily monotheism are born under the cape of fear, especially christians, when they encounter athiests/agnostics, it must amaze them that we're normal and not afraid to believe or not believe what they have been taught since birth. For some they can't deal with it, and eventually run away. As a witch, I dealt with that alot. People we're amazed that I didn't burst into flames upon entering churches for weddings or funerals. We're free of fear and open to live our lives the way we feel.

Maybe they are spies

From my own personal experience (as a once religious person), they do it for two reasons.

1. To help: they honestly want to save people from Hell

2. They think they're fighting evil (if you're not for God you're for Satan in their minds)

Because part of their religion is getting everybody to believe in what they believe in. They think it's their duty to enlighten everybody.

There are plenty of faith based dating sites and faith based community sites.
Many join for the same reason Mormons knock on your door.
Some are actually curious enough to engage their understanding to the positions held by AnA.

I have good friends who are religious and they never ever try to change me in any way although I have had experiences of being 'converted' my worst was getting on the wrong train -non stop to sevenoaks from London croded so we were squashed into the corridor with a holy man preaching at me non stop and telling me he would pray for me . Basically I think they like the idea/job of converting souls. I was a lecturer in person centred counselling I did my initial training with two priests, a vicar ,two nuns and a deaconess and they were pretty good fun

I'm a questioning Christian and I'm here to get answers that I have been condemned to ask in church. I love answers that use logic though the basis of christianity is to dismiss logic to understand God. If anything I'm being converted to apostate. I appreciate the patience and responses I get from this site.

Maybe they want to infiltrate and learn the secrets of the heathens, to have a more solid strategy to win more souls for their master.