Identification of the faiths of the realms are usually included in a name, supplanting any family or noble names. Amaster, a cleric of Tymora, can be referred to as Amaster of Tymora without incident. In higher church circles and matters involving leaders of particular temples or faiths, the full title is important, such as Asgaroth of Tempus, Patriarch of Baldur's Gate.
* Source: Ed Greenwood and Jeff Grubb. "Forgotten Realms: A Grand Tour of the Realms." Lake Geneva, W.I.: TSR, 1993, 23.