I don't see a conflict of beer drinking and practicing the Christian faith. Many monasteries actually were making their own beers, some may still. I think there is a puritanical mindset still flavoring much of America that has this belief that a Christian must deny anything when in practice we are really for everything that is good, "all things to all" comes to mind from St. Paul. St. Thomas Aquinas is known to have said that drinking is good to the point of hilarity which became a topic of conversation during my fraternity's chess playing days. Besides, Christ transformed water into some pretty incredible wine!
Surely it was a little presumptuous of Sunglasses man to assume you were a Christian because you write about faith and religion?
The man obviously had little in the way of respect or manners. I can honestly say that I have never broached the subject of a person's belief unless they have first raised it as a topic of conversation.
Pro tip: Avoid anyone who gives their name as "Sunglasses man".