Lex orandi, lex credendi
“The law of prayer is the law of belief.”
Christian theological maxim, after Prosper of Aquitaine
What does “Lex orandi, lex credendi” mean?
Lex orandi, lex credendi translates as “The law of prayer is the law of belief.”
How a community prays shows and shapes what it believes.
“Lex orandi, lex credendi” word by word
| Latin | English | Grammar |
|---|---|---|
| Lex | law, rule | nominative singular (feminine) of lex, “law”; subject of the first half |
| orandi | of praying | genitive singular of the gerund of oro, “I pray”; the “law” belongs to praying |
| lex | law, rule | nominative singular (feminine) of lex, “law”; subject of the second half, with “is” understood |
| credendi | of believing | genitive singular of the gerund of credo, “I believe”; the “law” belongs to believing |
How to pronounce “Lex orandi, lex credendi”
Both pronunciations sound the same here, since there is no c or g before e or i and no v. Stress the second syllable of orandi and credendi.
The story behind it
Word for word the line says “the law of praying, the law of believing”, with the verb “is” left out, as often in Latin maxims. It sets two things side by side: how people pray and what they believe.
It goes back to Prosper of Aquitaine, a Christian writer of the 5th century, who argued that the rule of praying should establish the rule of believing. The short two-part form used today is a later condensation of that idea.
The maxim is much cited in Christian liturgical theology. It is usually taken to mean that worship both expresses and shapes a community’s faith, so the way a church prays is evidence of what it teaches.
How to use “Lex orandi, lex credendi”
Suited to writing or talks on worship, liturgy and church tradition, or as a motto for a congregation, choir or religious study group. It also fits a tattoo or print for someone who sees practice and conviction as bound together.
- Latin
- Lex orandi, lex credendi
- English
- The law of prayer is the law of belief.
- Source
- Christian theological maxim, after Prosper of Aquitaine
- Era
- Late Antiquity
- Theme
- Faith
Common mistakes
- “Lex” here means rule or principle, not a state law or legal statute.
- The endings orandi and credendi are genitives of the gerund, “of praying” and “of believing”. Changing them to orare or credere gives different, incorrect Latin.
- It is often quoted as ancient Roman wisdom, but it is a Christian theological maxim from Late Antiquity, shortened in later tradition.
- Some versions add a third clause, “lex vivendi” (law of living). That is a later extension, not part of the original formula.
Questions about “Lex orandi, lex credendi”
What does “Lex orandi, lex credendi” mean literally?
“The law of praying, the law of believing”. Latin leaves out the verb, so English supplies “is”: the law of prayer is the law of belief.
Who said “Lex orandi, lex credendi”?
The idea comes from Prosper of Aquitaine, a 5th-century Christian writer. The short, balanced wording is a later condensation of his principle.
How do you pronounce “Lex orandi, lex credendi”?
Say “leks oh-RAHN-dee leks kreh-DEN-dee”. The Classical and Church pronunciations sound the same here.
Is “Lex orandi, lex credendi” correct Latin for a tattoo?
Yes, it is correct and complete as a maxim. Keep both genitive endings, orandi and credendi, exactly as written.
More to explore
Translation and grammar checked by Latin Quoter · last reviewed November 2026
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