Real Life Minute:
Which is more important: believing the right thing, or doing the right thing? St. Cyril of Jerusalem tell us that both things are essential:
For the method of godliness consists of these two things, pious doctrines, and virtuous practice: and neither are the doctrines acceptable to God apart from good works, nor does God accept the works which are not perfected with pious doctrines. For what profit is it, to know well the doctrines concerning God, and yet be a vile fornicator? And again, what profit is it, to be nobly temperate, and an impious blasphemer? A most precious possession therefore is the knowledge of doctrines.