St. Alphonsus Liguori

Here a question arises, whether it is necessary to have recourse also to the intercession of the saints to obtain the grace of God.

That it is a lawful and useful thing to invoke the saints, as intercessors, to obtain for us, by the merits of Jesus Christ, that which we, by our demerits, are not worthy to receive, is a doctrine of the Church, declared by the Council of Trent: 'It is good and useful to invoke them by supplication, and to fly to their aid and assistance to obtain benefits from God through his Son Jesus Christ.'

Such invocation was condemned by the impious Calvin, but most illogically. For if it is lawful and profitable to invoke living saints to aid us, and to beseech them to assist us in prayers, as the prophet Baruch did: And pray ye for us to the Lord our God (Bar. 1,13) and St. Paul: Brethren, pray for us (1 Thes. 5,25); and as God himself commanded the friends of Job to recommend themselves to his prayers, that by the merits of Job he might look favorably on them: Go to my servant Job,...and my servant Job shall pray for you; his face I will accept (Job 42,8); if, then, it is lawful to recommend ourselves to the living, how can it be unlawful to invoke the saints who in heaven enjoy God face to face? This is not derogatory to the honor due to God, but it is doubling it; for it is honoring the king not only in his person but in his servants. Therefore, says St. Thomas, it is good to have recourse to many saints, 'because by the prayers of many we can sometimes obtain that which we cannot by the prayers of one.' And if anyone objects, But why have recourse to the saints to pray for us, when they are already praying for all who are worthy of it? The same Doctor answers, that no one can be said to be worthy that the saints should pray for him; but that 'he becomes worthy by having recourse to the saints with devotion.'