I'm sure the vast majority of all Christians believe in and use birth control.
But church leaders do not promote birth control, even if most do not banish it.
More importnatly, conservative politicians act to remove public access to birth control.
It was a big issue with the ACA that they did not want access to birth control to be a minimum coverage for healthcare.
They are vehemently against Planned Parenthood which primarily is for women's reproductive health and assistance to access birth control.
Republicans throw up barrier after barrier to impede any public resources to help women easily and safely prevent unwanted pregnancies.
They take the resources away which means there will be more unplanned pregnancies putting women in a situation to make very difficult decisions.
And that will lead to more abortions, which nobody wants, or the need of public taxpayer assistance to help raise children born in poverty.