I can't say for sure, but I have been helped many times by people, so I imagine some were Atheists, while others were Agnostic, or religious. It does NOT matter, help is help.
During a dreadful situation, such as after a hurricane, I think people just generally pitch in and help and it does not matter if Jewish, Catholic, Protestant, Mormon, any other religion, or Atheist, they all just help.
For us to go around trying to nit pick who does what or why, is foolish. For us to start saying ONLY a certain group of people help, we are then putting ourselves on a Pedestal, and God is not happy with that.
So regardless of our religious preference, if someone needs help, just help him and leave our preference OUT OF IT.