Add Health adolescents were asked if they had ever had sex. Here is the percent who answered yes by church attendance (whites, sample size = 5,555)
Percent who have had sex
Never attends 47.3*
Less than once a month 48.5*
Between once a month and less than weekly 42.4*
Weekly or more 30.8
*significantly more than "weekly or more"
The percentages are significantly higher for those going to church less often or never. But perhaps among kids who have sex, the religious ones fail to use protection.
Percent who used protection the first time
Never attends 66.1
Less than once a month 71.6
Between once a month and less than weekly 68.9
Weekly or more 65.0
The differences among these groups are all statistically non-significant.