First, there is nothing wrong with what she said here. Civilizations live when they are aware of the value of their culture. If you want a Christian Germany, go to church every once in a while, explain the Bible to a Muslim, etc.
Politically, it is not cluelessness either. The European Union project, set up from the beginning as a religiously-indifferent customs union now has to face the consequence of their secularism. The EU has two possibilities: dissolve, re-establish national currencies and national borders, and deal with refugees as nation states. Or restructure itself as a specifically and exclusively Christian union and deal with the refugee crisis accordingly. Neither decision is entirely hers to make, but if Germany is to remain the de-facto leader of EU, the second option is the one they should move towards.
Oh, I have no problem with her encouraging people to examine their religious heritage. That part was great.
My problem is with the statements that she made about how great it is to have the invaders in her country. That is where she is clueless. This will not end well.