Here is the oration that the Church prays in the Mass and Office for the Twenty-Fourth and Last Sunday after Pentecost:
Excita, quǽsumus, Dómine, tuórum fidélium voluntátes: ut, divíni óperis fructum propénsius exsequéntes; pietátis tuæ remédia maióra percípiant.
Here is my translation:
Arouse, O Lord, we ask Thee, the free wills of Thy faithful: that, more eagerly pursuing the fruit of divine works, they may partake in the more abundant remedies of Thy loving-kindness.
Here is the translation from the Divinum Officium site:
Stir up, we beseech thee, Lord, the wills of thy faithful people, that they, plenteously bringing forth the fruit of good works, may of thee be plenteously rewarded.
I chose to translate “divíni óperis” very literally as “divine works,” rather than “good works” (or even “supernatural works,” which would be justified) because, not only is it more faithful to the Latin, but it also shows that the source of such works is divine. In other words, we perform supernaturally good works that are meritorious before God only by the help of His grace. The resulting “more abundant” remedies of God’s loving-kindness is an example of our cooperation with grace being rewarded. This prayer is a lovely illustration of what Saint Augustine meant when he said, “Therefore he crowns you because he crowns his own gifts, not your merits” (Ergo coronat te, quia dona sua coronat, non merita tua). Of course, Saint Augustine believed in the Catholic notion of personal merit (see here), but our merit must have it source in divine grace. In the context of this well-known passage, Saint Augustine is speaking of our merits specifically “before grace.” His disciple, Saint Fulgentius, gave an excellent explanation of the teaching of his Master:
Indeed, a man who has been justified, that is, who from impious has been made pious, since he had no antecedent good merit, receives a gift, by which gift he may also acquire merit. Thus, what was begun in him by Christ’s grace can also be augmented by the industry of his free choice, but never in the absence of God’s help, without which no one is able either to progress or to continue in doing good (Responses on Behalf of Augustine 6 [A.D. 431]: source).
Without God arousing, stirring up, or exciting our free wills with His grace, those wills can do no supernaturally meritorious good works. Without divine grace, we are all hellbound. Let us be thankful for the gift of grace and, with the Church, ever pray for it.
A note on the name of this Sunday: “Depending on the date of Easter, there may be as few as 23 and as many as 28 Sundays after Pentecost […]. The Masses for these ‘extra’ Sundays come from the Season after Epiphany, which is shortened if Easter comes early, thereby making the Season after Pentecost longer” (source). Regardless of how many Sundays take place between Pentecost Sunday and the First Sunday of Advent (of the new liturgical year), this particular set of propers — for “the Twenty-Fourth and Last Sunday after Pentecost” — is always used on the last Sunday of the liturgical year.