In Aion, there are two factions available for players to choose from. One faction is the angelic Elyos, and the other are the demon-like Asmodians. Many multi-player online role-playing games have big differences in class skills and starting stats for different races and factions, but this is generally not the case in Aion. Each Aion faction has only one playable race at this time, and other than appearance and questing area differences, they are almost completely identical.
Both Asmodian and Elyos Priests start the game with 201 hit points and 375 mana points. They both receive the same Priest and later Cleric skills and spells, and although sometimes the abilities have different names, they do the same thing for each race. In early versions of the game there were different Daeva Point skills for each race, but that has since been changed. There are only one or two abilities that have a substantial difference between them. The only reason to choose one race over another is for aesthetic or lore purposes. It is possible that certain stigmas stones only drop for one race or the other, but that hasn’t been tracked or proven yet. So pick the race you’re the most interested in to be your Cleric, and don’t worry that you’re choosing the one with less effective abilities or stats.
