Favored Soul/Sorcerer/Mystic Theurge

[Shin Okada]

Is there any way for a Favored Soul 4/Sorcerer 4 to gain 6 ranks of Knowledge (religion)? Say, by taking some heritage feat and such?

 

[Dandu]

Yes. Yes there are.

He should also take Heighten Spell and Versatile Spellcaster to qualify for Mystic Theurge at level 4, assuming 3 skill points/level.

 

[Dannyalcatraz]

Knowledge Devotion Feat (CompChamp): One Knowledge skill of your choice is a class skills (like KS:Religion) regardless of the class you are advancing. Whenever you fight a creature, you can make a Knowledge check based on its type, provided that you have at least one rank in the appropriate Knowledge skill, gaining an insight bonus on Att/Dam rolls against that creature type for the remainder of the combat.