A truth revealed by God that Catholics must believe is the
Holy Trinity.
Here's why it's central and important:
* Core Doctrine: The Trinity—God as Father, Son (Jesus Christ), and Holy Spirit—is the foundational doctrine of the Catholic faith.
* Revealed Truth: Catholics believe this is not something humans could have figured out on their own, but rather a truth revealed by God in Scripture and Tradition.
* Essential for Salvation: Belief in the Trinity is considered essential for salvation because it defines who God is and how we relate to Him.
* Expressed in Creeds: The doctrine is formally expressed in creeds like the Nicene Creed and the Apostles' Creed, which Catholics profess during Mass and other liturgical events.
While there are *many* other doctrines and truths Catholics believe, the Holy Trinity is arguably the most foundational and distinguishing truth revealed by God that Catholics must believe.