Chairity wont allow atheist to help.

[Captain Colostomy]

And are you just hell-bent on painting the atheist group as being as big of bigoted assholes like the woman running the soup kitchen? Is it "two wrongs make a right" day? I really doubt that any atheist or humanist group would turn down help from religious groups unless those religious groups were intent upon preaching instead of actually helping.

And how would you determine their intent?

If they asked if they could wear t-shirts that say Jesus Saves to your event, would you be suspicious that their intent was preaching?

A suspicion. Whoop-dee-do. It's a charity. It's for helping the less fortunate, first and foremost...or is it? If everyone acted on their suspicions, we'd all be aiming guns at each other.