If god weren't there, people wouldn't be charitable? Rubbish!
Atheists like Warren Buffet & agnosts like Bill Gates have given billions to charity. Non denominational gruops like Doctors without Borders work extremely hard helping the less fortunate.
Oh, & their charity isn't with the aim of insidiously bringing more souls to Christ so its that much more noble, its done simply with the aim of being good, without expecting anything in return!