Religions are born often, but every religion eventually gets a creed. In an earlier post I reported on two of the major world religions, describing how they each acquired a creed some years after the founder's day.
Stephen Batchelor, a western Buddhist found that both Christianity and Buddhism existed for many years without being circumscribed by a body of theological material considered requisite for practicing members of the faith. Then it happened; the priests decided what everyone should/must believe. Thus were born creeds.
William Blake described this process with greater cogency and eloquence:
Till a system was formed, which some took advantage of & enslav'd the vulgar by attempting to realize or abstract the mental deities from their objects: thus began Priesthood;
Choosing forms of worship from poetic tales.
And at length they pronounc'd that the Gods had order'd such things.
Thus men forgot that All deities reside in the human breast." (The Marriage of Heaven and Hell), and later he wrote "I must create a system or be enslaved by another man's." Individuals perceive creeds in that way, as the mind forg'd manacles (Blake again).
The net effect of creeds is to restrict individuality. Russian communism is the most horrible example in our times, but it has been repeated and repeated throughout the sad history of the world.
When individuality is restricted, creativity diminishes, and the end result is a society of drones ruled by a handful of masters. This is equally true in the religious, social and political realms. God protect us from such an outcome.