creed
A set of important beliefs or principles someone lives by.
A creed is a formal statement of beliefs that a person or group holds to be true. When someone states their creed, they're explaining the core principles that guide how they think and act.
Religious groups often have creeds that summarize their most important teachings. The Apostles' Creed and the Nicene Creed are ancient Christian statements of belief still recited in churches today. Creeds extend beyond religion, though. A school might have a creed about honesty, respect, and learning. A sports team might develop a creed about teamwork and perseverance.
Your personal creed is the set of values you refuse to compromise, the beliefs that shape your decisions. Someone whose creed includes courage and honesty will speak up when they see something wrong, even when it's difficult. A scientist whose creed values truth above popularity will report findings accurately, even if the results disappoint people.
The key thing about a creed is that it represents principles you actually live by, words that translate into action. When someone says “that goes against my creed,” they mean it violates something they believe so deeply that they can't ignore it. Your creed is what you stand for when it really counts.