I know it's rare (!) but every so often you'll find someone who accepts evolution, but who is also a Christian. What I've found is it's better to skip straight to two questions when debating them.
What was the point of Jesus' sacrifice?
Why is there suffering in the world?
Now, no matter how much they try to duck and dive and twist scriptures, they can be shown that the two are not compatible. It's worse than them having to take Genesis as one big metaphor (or mistake, as I like to say). It really destroys the basic foundations of that religion, in a way which effects all Christian sects I've come across.
To show you what I mean, here's two debates I've had on the subject. I didn't have to use all the arguments I have on this (I have a master copy 'essay' I tweak sometimes) , but so far it looks like I have it covered.
I would recommend taking this approach if you think they may be open to reason, or if people reading along may be. It saves a lot of bother going over other reasons why it's unlikely this god exists. This way disproves the existence of the god written about in the Bible in a clearer way.
In this one, it's mostly between Matthew, who comes in at post 8, and myself - Chris J - from post 23 on. I talk to a couple of others there, but he puts more into it.
This is the latest one. Between Micheal Erickson and myself - Chris J again, funnily enough.
I'm still waiting for responses on both of them. Ah well.