@MangAnimeJe & @Bessieboo
You can have religion in sims 2 with mods and there is a ton of religious artifacts and furniture cc out there as well.
Working religions. Make your own gods/goddesses and choose what morals each religion follows. You'll want to use an NPC clothing changer on the nun who is included, because she is wearing a distinctly unnunlike outfit.
http://backalleysims.com/adultsite/...T-amp-A-A-amp-N
Instructions for faith.
http://www.backalleysims.com/adults...d-A-amp-N-stuff
The above 2 are just part of a much bigger list
http://modthesims.info/t/529253
sims 3 also has the Sims 3 Priest Career run in conjunction with Nrass Career mod..
http://modthesims.info/d/428999
http://nraas.wikispaces.com/Careers