From his lips to God's ears...................

Fundamentalists are literally out-breeding moderates within Islam, Roman Catholicism, Protestantism, Mormonism and Judaism. Ultra-Orthodox Israeli Jews have an average of 7.5 children; secular ones 2.2. In cities in Muslim countries, women who are most in favour of Sharia have twice as many children as women who most oppose it.

Fortunately, children often do the opposite of what their parents tell them, and religious revivals have a tendency to fade. 

-Matt Ridley, as excerpted from this post on Europe's current "migration" crisis