mystery

The truth behind the events remains a mystery.

That man is a mystery.

...and, not knowing the meaning or misterie of her pollicie, forgat no termes of reproche or rigorous rebuke against his chast doughter.

If God should please to reveal unto us this great mystery of the Trinity, or some other mysteries in our holy religion, we should not be able to understand them, unless he would bestow on us some new faculties of the mind.

There are seven mysteries, or sacraments, in the Greek church, viz. baptism, the chrism (a rite peculiar to this church), the eucharist, confession, ordination, marriage, and the holy oil.

the Eleusinian mysteries

The second decade of the Rosary concerns the Sorrowful mysteries, such as the crucifixion and the crowning with thorns.

The trades, the crafts, the mysteries, would all be losers.