Sacrosanct (adjective)

1. Consecrated or inviolable by virtue of religious or moral principles.
2. Entitled to respect and reverence; inviolable.

Origin:

From latin sacrosanctus, from sacer ("sacred") + sanctus ("hol.y")

Examples:

1. The Constitution is sacrosanct in the eyes of many Americans.
2. The holy book is sacrosanct to the faithful.
3. The sacrosanctity of human life.
4. The sacrosanct nature of marriage.
5. He considered the rules of the game to be sacrosanct.