I am trying to figure out how Christians can be reached in terms of eval, especially because EA messaging really isn't landing too well in my conversations with Christians. 

This sounds like a question that might benefit from testing how Christians (though, of course, this is a heterogeneous group) respond to different messages about charity or about evaluation specifically.

I would also add that I think that a lot of what is distinctive about EA is not to do with charity evaluation specifically, but to do with wanting to maximize impartially. Many, many groups want to know whether their charities of interest are pursuing their (narrow) goals effectively. Many fewer want to know whether their favoured narrow goals (e.g. help the whales, help some specific village) is impartially helping (considered across all domains) to the greatest extent possible.

Might be worth looking at GWWC's evaluators research to get an overview of our thinking about some of this. Not exactly what you're looking for, but might be helpful.