Christians, are you charitable because of your religious beliefs or are you just a charitable person?

I think it's a bit of both.

Religious organizations provide an effective way for charitable people to practice their charity.

Whatever charity I have is because of the work of Christ within me through the Holy Spirit. Before I cam to Christ, I was not a charitable person at all. I seriously doubt I could continue to be one without His continued work in my heart.

Well, the Bible answers this question. "Faith without works dead." We know that works are not how we get into heaven and yet without working we are not worthy of the name. I know it sounds like circular logic and yet I assure you it is true. No man or woman will enter Heaven without proclaiming Jesus and the only ones that will enter without works will be last minute entries like the thief on the cross and true death bed confessions. Perhaps it is our definition that is flawed. We seem to think it terms of doing and that is laughable. God has already done and we are tools or if you will fruit. Look at all the imagery in the Bible it deals with harvest and fruit. If the true vine is in us we will bear much fruit and others will not only see the fruit but take the fruit and eat of it. My Pastor gave an illustration two Sunday's ago. When you bear fruit people will climb that tree, scraping the bark, tearing at the limbs and perhaps even chop the tree down to get at all the fruit on it. For the tree it is not so good, but that is what we are called to do.

By God's grace, I'm a charitable person.

~added~

Your lack of belief is as insignificant to me as it is predictable.

A bit of both.