This article describes the higher birthrate of Muslims, which is projected to make the Muslim population surpass the Christian population by 2070. The article speculates that violence will be a likely result as shifts in power take place.
These demographics should help Protestants understand why Roman Catholics have maintained there views on birth control (that is, not using birth control). In the Near East, Christians and Muslims have adopted harsh customs to ensure that members of their communities do not cross over to the other religion due to the dangers that go along with depopulation. Marrying into the other religion will mean getting shut out of the family and could even mean death, things hard for those in the west to understand.