Religion

I'm sure there are those who credit their religion for their good deeds, but such people would probably be doing such things with or without religion. So it may be true that organized religion facilitates such things, but it's really a very inefficient way to do it given most of their resources are going to other things.

If one imagines a world without organized religion, people would still be forming benevolent secular organizations to help other people. You'd still have people donating and volunteering to those organizations. The difference would be you wouldn't be expending a lot of resources doing things that really have absolutely nothing with helping anyone.

So even if you disregard all the bad things that organized religion does, which is significant, you are still left with a poor substitute for doing anything truly meaningful.