I am agnostic. I have only taken to putting it into words for the past couple months now, but I believe I had arrived there a couple years ago.
That said, I believe that even atheists and agnostics might benefit from finding a church. Many churches are quite liberal in doctrine, others are just generally accepting of people. The people one generally meets there are good people. They would make good friends in many cases. Small talk will soon point you toward those who share your hobbies and interests. Then the 'friend seeker' probably needs to take the bull by the horns a bit and get involved in clubs or meetups that the people you met are involved with. In other words, churches could be a good source of friendly meetings that could lead to real friendships over time.
I am not good at that. I am generally considered outspoken, but get fairly shy in a crowd. It has been hard for me to follow my own advice here, but I do believe it could work for some seeking to expand their friendships.
Personally, I have a very small group of friends. No one ever visits my home just to see me, unless it is family. I meet a few xjws for dinner a couple times a year. I stay in touch with many xjws, and a few who never were on facebook. Part of my problem is the rural area in which we live. But retrospectively, if I had never been a Jw that might have been the case also. Personality coupled with environment are key.
Jeff