Hi. What you say works well in the pragmatic sense. But I'd say that we can still find arguments to support that Christianity is also true.

I wouldn't worry about philosophy finding certainty and replacing faith - it's not going to happen. To be very strict, certainty is only found in pure logic and mathematics. For everything else, truth is at best only reasonable or probable. And true faith is not blind but supported by reason. It is "the act of believing and behaving based on knowledge that is not certain yet reasonable".