There is always the argument that Christians give, “You just have to have faith”. They then throw out the following.

You have faith when you sat in that chair.

You have faith when you start your car.

You have faith you will wake up each morning.

So why don’t you have faith in god?

Well, let’s cover this argument shall we.

You have faith when you sat in that chair.

Sure, because I know it’s going to hold me. After all most of the chairs I sit in I have sat in before. So I know they will probably hold me again. But we are talking about faith in an observable, visible physical object. I can see it, test it and determine that it will probably hold me. The faith in the chair is earned based of my observations.

You have faith when you start your car.Now give me an old chair that’s a little beat up, and I will have some doubt and will sit in it with a little caution and doubt, but will also test it to be sure it will hold me. (via godisnotgreat)

There’s quite a bit more to this response, and well worth a read.