**From the Navarre Bible Commentary
Second Reading - From: Hebrews 11:1-19 [red text not included in Sunday's Reading]
The Good Example of the Patriarchs
 Now faith is the assurance of things hoped for, the conviction of things not seen.  For by it the men of old received divine approval.  By faith we understand that the world was created by the word of God, so that what is seen was made out of things which do not appear.  By faith Abel offered to God a more acceptable sacrifice than Cain, through which he received approval as righteous, Gen 5:24 God bearing witness by accepting his gifts; he died, but Sir 44:16 through his faith he is still speaking.  By faith Enoch was taken up so that he should not see death; and he was not found, because God had taken him. Now before he was taken he was attested as having pleased God.  And without faith it is impossible to please him. For whoever would draw near to God must believe that he exists and that he rewards those who seek him.  By faith Noah, being warned by God concerning events as yet unseen, took heed and constructed an ark for the saving of his household; by this he condemned the world and became an heir of the righteousness which comes by 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.  By faith he sojourned in the land of promise, as in a foreign land, living in tents with Isaac and Jacob, heirs with him of the same promise.  For he looked forward to the city which has foundations, whose builder and maker is God.  By faith Sarah herself received power to conceive, even when she was past the age, since she considered him faithful who had promised.  Therefore from one man, and him as good as dead, were born descendants as many as the stars of heaven and as the innumerable grains of sand by the seashore.
 These all died in faith, not having received what was promised, but having seen it and greeted it from afar, and having acknowledged that they were strangers and exiles on the earth.  For people who speak thus make it clear that they are seeking a homeland.  If they had been thinking of that land from which they had gone out, they would have had opportunity to return.  But as it is, they desire a better country, that is, a heavenly one. Therefore God is not ashamed to be called their God, for he has prepared for them a city.
 By faith Abraham, when he was tested, offered up Isaac, and he who had received the promises was ready to offer up his only son,  of whom it was said, "Through Isaac shall your descendants be named."  He considered that God was able to raise men even from the dead; hence he did receive him back, and this was a symbol.
- Although the text does not aim to provide a precise definition of faith, it does in fact very clearly describe the essence of that virtue, linking it to hope in future things and to certainty concerning supernatural truths. By means of faith, the believer acquires certainty concerning God's promises to man, and a firm conviction that he will obtain access to heaven. The Latin translates as "substantia" the word the RSV translates as "assurance"; "substantia", which literally means "that which underlies", here refers to the solid basis provided by hope.
This verse indicates that faith, which is a type of knowledge, is different from other types of human knowledge. Thus, man can know things by direct evidence, by reasoned proof or by someone else's testimony. As regards knowledge based on information provided by
someone else, that is, knowledge based on faith, we can distinguish two types--human faith, when it is another human being whose word one relies on (as in the case of pupil/teacher, child/parent), and supernatural faith (when the testimony comes from God himself, who is Supreme Truth). In this latter case the knowledge provided is most certain.
However, the object of supernatural faith, that is, what one believes in (God and the unchanging decrees of his will), is not something that is self-evident to man, nor is it something that can be attained by the use of unaided reason. That is why it is necessary for God himself to bear witness to what he reveals. Faith, then, is certain knowledge, but it is knowledge of things which are not self-evident, things which one does not see but which one can hope for.
The verse also says that faith is "conviction" concerning things not seen. It is therefore different from opinion, suspicion or doubt (none of which implies certainty). By saying that it has to do with things unseen, it is distinguishing faith from knowledge and intuitive cognition (cf. "Summa Theologiae", II-II, q. 4,a. 1).
Summing up, we can say that "when God makes a revelation, we are obliged to render by faith a full submission of intellect and will. The faith, however, which is the beginning of human salvation, the Catholic Church asserts to be a supernatural virtue whereby, with the inspiration and help of God's grace, we believe that what he has revealed is true--not because its intrinsic truth is seen by the natural light of reason, but because of the authority of God who reveals it, of God who can neither deceive nor be deceived" (Vatican I, "Dei Filius", chap. 3).