In some sense, we as humans are very lucky. I would be willing to bet that nearly all of mankind wants the world to be a better place. Atheists, christians, muslims, nazis, etc. all want the world to be a better place. The only difference is what they think makes a place better. However, these different ideas, especially when not examined rationally, result in either a non-optimal positive impact on society or even (probably more often) a negative impact. According to The Barna Group, in the year 2000 over 3/4 of Americans donated to a non-profit organization or church, giving a total of near $100 billion. Barna also estimates that 6 out of every 10 of those dollars, or $60 billion, goes specifically to churches. $60 BILLION! Now sure, some of these people would not be giving to charity if it weren't to the church. Some people want to fund church activites simply because they're church activities or they want to help "spread the faith". I'm guessing that that value doesn't exceed $20 billion. The other $40 billion I believe comes from people who want to give back to the community and think that giving to the church helps society and helps America. And it's easy to make a contribution to the church, there's two contribution envelopes for every bible. Unfortunately, this $40 billion contribution goes to speading lies and furthering religious beliefs that endanger humanity's survival. Now sure, some of that money will end up for a canned-food drive which actually does help people. But most of it will go to faith-based activities, which actually result in a negative impact on society in the long-term.
Imagine what that $40 billion could do if it were used for an actual good purpose? $40 billion in one year dedicated to scientific research for fighting diseases would be absolutely amazing. $40 billion to help pay our teachers better salaries would be great. $40 billion to help kids with cancer. $40 billion to send under-priveleged kids to college. $40 billion to feed starving people in Africa. $40 billion to pay off the national debt. $40 billion! Or we could use it to spread fucking myths and ideas which are toxic to civil rights, healthy living, and scientific progress. Hmmm....tough call.
What can do we about this? If you've got a parent, a coworker, a friend, etc. who you know likes to give back and chooses to do so via the church or another faith-based organization, you could simply tell them about a secular, non-profit organization which you support and really try to sell them on it. You don't have to hurt their faith or attack the church, just let them know that the church has plenty of money and that these other charitable organizations don't get the money they need because they lack the visibility and convenience of donation of the church.