act of faith

American  

noun

1. an act that demonstrates or tests the strength of a person's convictions, as an important personal sacrifice.

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act of faith British  

noun

1. Christianity an act that demonstrates or tests a person's religious beliefs

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act of faith Idioms  

1. Behavior that shows or tests a person's religious or other convictions, as in Rock climbing with a new, inexperienced partner was a real act of faith. The term is a translation of the Portuguese auto da fé, which referred to the sentencing and execution of heretics (often by burning at the stake) during the Inquisition, when punishing heresy was thought to constitute an assertion of faith. In modern times it is used for more benign circumstances. [Early 1700s]

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Example Sentences

"I have been witnessing miracles of healing through the years because of this act of faith."

From Barron's • Apr. 3, 2026

The Catechism of the Catholic Church teaches that Mary’s consent—“Let it be done.”—was a free, active and essential act of faith that allowed the Incarnation to occur.

From The Wall Street Journal • Mar. 18, 2026

The act of faith, of believing, is by definition something that can’t be seen.

From Los Angeles Times • Jan. 8, 2026

For them, a pilgrimage to Mazu's home temple in Meizhou in southern China is an essential act of faith.

From BBC • Dec. 29, 2023

When you put it in words it sounded reasonable; it was when you looked at the human beings passing you on the pavement that it became an act of faith.

From "1984" by George Orwell