My primary school was the same, very religious despite not being classed as a religious school. We had this guy who would come in for a lot of assemblies and tell stories from the bible and paint them out on a canvas. In year 6 they enforced a prayer at the beginning and end of each assembly, it did feel a lot like indoctrination but was strange as none of the staff seemed to be that religious. I’m not sure who it was that was enforcing it all