Tenet (noun)

1. A principle, belief, or doctrine that is accepted as true and forms the basis of a particular theory or system.
2. A principle that is held to be true by a particular group or individual.

Origin:

From the latin word tenere meaning "to hold".

Examples:

1. The tenet of their religion is love and compassion.
2. The tenet of their political party is to create a just society.
3. The scientific community holds the tenet that theories must be tested and supported by evidence.
4. The tenet of their philosophy is to always do what is right.
5. The tenet of the company is to always put the customer first.