I have a friend who has been a daycare provider for maybe 20 years and she makes it evident that she runs a Christian daycare and will teach prayer and Christian beliefs so she attracts those clients who respect her for that. However, I believe that religion is a personal family thing and should be taught at home by the parents since there are so very many variations on beliefs, even among Christians.
We celebrate all the holidays in kid-mode, Easter bunny, Santa Claus, etc. at my daycare without religion involved. I check with parents at the contract signing stage if it is alright with them if we celebrate birthdays and holidays so that I know it won't offend anyone. If I ever have a family request religious teachings or grace at mealtimes I will be open to their request but I will definitely check with all the other families in my care to make sure I won't offend anyone in any way.
It's all about respect for everyone at all times. I expect my clients to respect and trust me and I respect them as well.