50 In presenting the story of the patriarchs and the righteous men and women of the Old Testament, the Letter to the Hebrews highlights an essential aspect of their faith. That faith is not only presented as a journey, but also as a process of building, the preparing of a place in which human beings can dwell together with one another. The first builder was Noah who saved his family in the ark ( Heb 11:7). Then comes Abraham, of whom it is said that by faith he dwelt in tents, as he looked forward to the city with firm foundations (cf. Heb 11:9-10). With faith comes a new reliability, a new firmness, which God alone can give. If the man of faith finds support in the God of fidelity, the God who is Amen (cf. Is 65:16), and thus becomes firm himself, we can now also say that firmness of faith marks the city which God is preparing for mankind. Faith reveals just how firm the bonds between people can be when God is present in their midst. Faith does not merely grant interior firmness, a steadfast conviction on the part of the believer; it also sheds light on every human relationship because it is born of love and reflects God’s own love. The God who is himself reliable gives us a city which is reliable.
Source: Lumen Fidei (Vatican.va)