Here is an extract from a very fine Advent homily given by Pope Benedict XVI in 2008:
"The cry of hope of Advent expresses all the gravity of our condition, our extreme need for salvation. Which is to say that we await the Lord not as some beautiful decoration to a world already saved, but as the only way of liberation from mortal danger."
What was so noteworthy about this is that it represented a turning away from the semi-Pelagianism which characterised the post-Conciliar selection of Advent Sunday collects; Benedict instead turned back to the authentic tones of the Sunday collects which they replaced. Three of these (and notice also the Ember Masses) did a moderately unusual thing in the Roman Corpus of collects: they began with an imperative verb for their first word. This, in turn, was taken from psalm 79/80: 'Excita potentiam tuam et veni ut salvos facias nos' (Coverdale: Stir up thy strength and come and help us); a cry from Israel to her God to come and save His vineyard; a psalm full of a sense of dereliction and of pressing supplication. This urgent prayer became the starting point of three of the Advent Sunday collects in the old rite (as well as of the Collect of the Sunday Next Before Advent). Here is the translation which the good old English Missal gives for the collect of Advent I:
Stir up, we beseech thee, O Lord, thy power and come: that by thy protection we may be found worthy to be set free from the dangers of our sins which beset us; and to be saved by thy deliverance.
Compare this with (my translation) the OF collect:
Grant, we beseech thee, almighty God, this will unto thy faithful people, that, running with good works to meet thy Christ as he comes, they may be set at his right hand and be worthy to hold fast the kingdom of heaven.
There is absolutely nothing heretical or even ill-judged in itself about this; it appears in the Gelasian Sacramentary as a postcommunion. And the Stir up prayer has, indeed, survived into the OF as a ferial collect on (just one) weekday. But in the old days, Stir up was heard by all the worshipping community because it was a Sunday collect; moreover, it was repeated on every vacant feria throughout its week.
Lorenzo Bianchi says this about the newer selection of Sunday Collects in the post-Conciliar Missal: 'A Pelagian turn of thought becomes apparent: which does not show itself in a failure to speak about grace, but in the way it is separated from a realistic consideration of the human condition; and the manner in which the grace of Jesus Christ is made into an optional extra: just an unnecessary ornament ... [in the Advent Sundays and Christmas collects of] the new Missal ... sin does not appear, or even expressions explicitly linked with this concept ... [instead] we find phrases which, making no mention of the fragility of the human condition, tend to bring to the fore the aspect of man's commitment'. In the old Stir up series of collects, Bianchi goes on, 'a far more continual and pressing use of the imperative is found ... in place of these imperatives, in Paul VI's Missal the final or consecutive subjunctive prevails. Thus, even on the level of syntax, we pass from the cry of petition, from a dynamic of pure petition, to a basically descriptive phraseology'.