I've found the only way to make friends/community as an adult outside of religion, at least for me, is to go to events relevant to my hobbies and interests. Yes it's difficult, but communities for just about everything are out there if you put yourself out there. If you choose events that occur regularly I've found you get to know people and make friends just by trying to become a regular face too.

If you don't have a hobby/interest with a local group, you can try picking new ones until you find one that clicks too. It does take some effort initially though. The shared interest is critical to removing barriers to making those relationships for me.