Divine spellcasters most frequently gain new spells in one of the following two ways.
Spells Gained at a New Level: Characters who can cast
divine spells undertake a certain amount of study between adventures. Each time such a character receives a new level of
divine spells, he or she learns new spells from that level automatically.
Independent Research: A divine spellcaster also can research a spell independently, much as an arcane spellcaster can. Only the creator of such a spell can prepare and cast it, unless he decides to share it with others.