Religion has an interesting impact on socialization.
In areas with predominately religious people/children, religion can be seen as another way of supporting each other, another topic of conversation etc. At least for the ones who belong to the majority religon from a specific area. For those who don't belong to any religion or belong to a minority religion of that area, it might have a negative effect because they might be ostracized due to their religious beliefs.
This was mostly secondary socialization.
In primary socialization, when a child is with his family, they can bring their child up with the beliefs of their religion and it also further strengthens their own beliefs as they pass them down to their child.
As we can see, there are many effects of religion on socialization :)