[LintMan]

Originally posted by MCArt:
A priest can raise Dominion only to the value of his priest level, i.e. a level 2 priest preaching in a Dominion-2 province is useless, while a level 3 priest is not.

Note, though, that a temple in the same province as the priest adds one to his effective level, so a L2 priest in a province with a temple can preach up to level 3 domain.

Maximum dominion is the gods base dominion (chosen at god selection time) plus the number of temples built to the god divided by 5. So gods with a weak dominion can build more temples to raise their dominion. I'm not sure if the current max is shown anywhere - maybe try clicking on the temple site info.

As far as priests continuing to preach after they've maxed out their own capability - I think it could still be useful sometimes, because it could help prevent the dominion from neighboring provinces from encroaching and lowering the dominion in your province.