Pub Crawl

Had an unintentional pub crawl last night. Started off in one pub where I go for my singing class, and where the Head of Finance went this week for a men's meeting (how times have changed!). Then the singing teacher decided we needed to visit another pub where we will be performing at a Bank Holiday Beer Festival. By this time it was dark, so there we were stumbling around in the muddy pub garden trying to find the best place for the 'cowsticks'. And to be polite, of course, we had to go inside after, where a fellow crossword puzzler helped me finish the cryptic from the Weekly Telegraph, over our drinks.

Here's a question for you.
Just what is church, as in the gathering of believers, for?
And can you find scriptural support for your answer?