Absent Christianity and masculine leadership, their culture was vulnerable; the muslims saw this, and invaded. Germans, and other Europeans, are paying for disrespecting their heritage. Demographically, they are past the point of no return.
I am the vine; you are the branches. If you remain in me and I in you, you will bear much fruit; apart from me you can do nothing.
If you do not remain in me, you are like a branch that is thrown away and withers; such branches are picked up, thrown into the fire and burned. John 15:5-6