CCC 2465 The Old Testament attests that God is the source of all truth. His Word is truth. His Law is truth. His “faithfulness endures to all generations.”1 Since God is “true,” the members of his people are called to live in the truth.2

1 PS 119:90; Cf. Prov 8:7; 2 Sam 7:28; PS 119:142; Lk 1:50.
2 Rom 3:4; Cf. PS 119:30.