I don't know. People who don't worship any gods are pretty terrifying to deities. If such philosophies caught on, it would do great harm to them. Far more, generally speaking, than their opposing deities are usually capable of.Plinth: Located in Trades Ward, this set of sacred rocks is kept as a place of worship and meditation for all faiths. Many long-dead deities hear from their worshipers only at the feet of the Plinth. For the record, the Monks of the Old Order eschew worship at the Plinth, preferring to leave their departed god alone, if in fact they ever had a god.
But there is a more decisive answer in the Forgotten Realms Guidelines that were put out to help people convert from 2.5 to 3.0 before the 3.0 campaign setting book was released:
The guidelines are no longer on the WotC site (obviously), but I found a copy here: http://members.verizon.net/chad.lubrech ... elines.PDFMonks of the Old Order do not worship any deity, thus they can never be raised from the dead.