CTB, I would say that Christians divorce at the same rate as others, and are not insulated from the society at large.
Actually, they do if you count everyone who uses the label "Christian" but a person who actually follows their beliefs as a Christian (goes to church, reads their Bible, etc.) are much less likely to divorce according to statistics.
It is likely that Christian teens have sex at the same rates as well, but feel like if they plan ahead, they are planning to "sin". If they ate overcome with desire in the heat of the moment, it removes some of it being their fault...Hence lower rate of contraceptive use.
I wonder how much is tied to poverty rather than Christian beliefs.