Earlier quoted context omitted.
Serious question: do you (or anyone else) think it's immoral to go to church as an atheist just to meet people? I get along really well with church people, but I simultaneously hate talking about religion.
Most churches would (or should) welcome a non-believer! Going to church in your situation would not be sneaky or deceitful. Even if you are very very very sure that the service is not going to make you into a Christian, that does not matter since the church will be pretty sure of the opposite. Plus you're not taking anything away from anyone, there is no reason to feel guilty. As shorthand advice: try to find a missi…
If you're uncomfortable with ministry, you can probably find a community service project without a "hidden agenda." For example, the goal of the above project wasn't to turn the kids into "little christians;" rather the goal was just to keep their literacy skills up during the summer while school isn't in session.
As an athiest, by working with a project like that, you'd be able to help do good in the community while still feeling a sense of fellowship with the others. I'm sure the other churchgoers would appreciate the help for the event even though you don't intend on "converting" or whatever.