Yea, I used to work in a soup kitchen regularly with a group from my church, a lot of the work and the people doing it are great - but we didn't evangelize and I think that's how it should work. As a religious organization feel free to support charities and note that your organization accepts people from all walks of life - even include pamphlets if you'd like... but the aggressive evangelism is where it gets weird - if dinner and shelter that I require to live is contingent on me accepting religion then that shifts religion from a freely associated faith into an exchange.