Catechism of the Catholic Church

145 The Letter to the Hebrews, in its great eulogy of the faith of Israel's ancestors, lays special emphasis on Abraham's faith: "By faith, Abraham obeyed when he was called to go out to a place which he was to receive as an inheritance; and he went out, not knowing where he was to go." ⁴ By faith, he lived as a stranger and pilgrim in the promised land. ⁵ By faith, Sarah was given to conceive the son of the promise. And by faith Abraham offered his only son in sacrifice. ⁶

146 Abraham thus fulfils the definition of faith in Hebrews 11:1: "Faith is the assurance of things hoped for, the conviction of things not seen": ⁷ "Abraham believed God, and it was reckoned to him as righteousness." ⁸ Because he was "strong in his faith", Abraham became the "father of all who believe". ⁹

147 The Old Testament is rich in witnesses to this faith. The Letter to the Hebrews proclaims its eulogy of the exemplary faith of the ancestors who "received divine approval". ¹⁰ Yet "God had foreseen something better for us": the grace of believing in his Son Jesus, "the pioneer and perfecter of our faith". ¹¹