Do you incorporate faith/religion in the Sims?

From the other side, I would say I am pretty religious - I spent 4 years studying the Bible and Christian History, and work for a church - but I have no religions in my game. Never thought about it with Sims 4, although did in Sims 2 when I built a church, etc. I am fascinated with the idea of the OP religious festivals and holidays. I may have to add a little Celtic religion to my game because of this thread!