The Lord said: I think thoughts of peace (Jeremiah 29, 11).
The frost upon the earth today suggests it clearly enough: liturgical summer is over. With that, then, we will leave aside our close study of the collects of the Mass, and turn our attention elsewhere.
For three Sundays in a row we will hear the same introit, which I quoted a moment ago: Dicit Dominus: Ego cogito cogitationes pacis. That is a profound sentence; we cannot pass it over lightly. What terror Jeremiah must have felt when taking up the pen to record it! I cannot see how it could have been anything other than a bewildering terror when this inspiration visited him. That the Most High, inscrutable God should reveal his thoughts to us! The very thoughts of God. Vain presumption to imagine it! And yet we must.
And what are these thoughts of peace that the Lord thinks? In truth, we could give a number of answers. One answer that comes readily to mind is Divine Providence. This Providence is the plan, daily unfolded, which reveals the wise thoughts of the Father. But for now—and for those of you who have suffered my preaching down these years this will come as little surprise—another answer presents itself: the liturgical year. The liturgical year, the cycle of celebrations of the sacred liturgy, are God’s thoughts of peace.
Remember that another way to refer to the liturgical year is to call it, ‘The Church’s Year of Grace.’ And so it is: from the First Sunday of Advent until the Last Sunday after Pentecost, the days make up a single year of grace. Each day rises with the assurance of the presence of the Most Holy Trinity. Therefore, when Our Lord says in the 14th chapter of St John that he would not leave us orphans, one of the ways he fulfills this promise is by means of the sacred liturgy and its yearly cursus of fasts and festivals.
Note well: God speaks in the present tense, not the past—dicit, not dixit; cogito, not cogitavi. These thoughts of peace are fixed within the eternal present of His being, not subject to change and inconstancy; they exist here and now. Exactly like the liturgical year.
But if it is the case that the sacred liturgy contains the peaceful thoughts of God, then surely we need a guide to listen to these thoughts and to receive them reverently and with understanding. In many ways that describes the office of the preacher. But even this preacher needs a help and companion. Thus I thought I would choose Dom Prosper Guéranger, re-founder of Benedictine life in France and eminent liturgical commentator. His exposition of the liturgical year has been read by generations of Catholics since its publication between 1841 and 1875 (which was the year of his death.)
So each Sunday beginning today and through Advent, I will study something of Abbot Guéranger’s commentary and share with you what I find.
But remember that this is no merely academic pursuit. The point is that we should refer every detail of our life to the sacred liturgy: our sorrows and perplexities; our weaknesses and our victories; our fatigue and our joy.—To the extent we are able to refer all things to the Church’s worship, we will make great strides in the spiritual life. With God’s help, the truth of the matter emerges along the way.
Summer is over; winter is ahead. A new liturgical year opens before us, and we hear: ‘The Lord says: I think thoughts of peace.’ He condescends to tell us so; we do well to listen. Abbot Guéranger points out where we are, and where we ought to be:
After the divine realities of this year of grace, we ought to be capable of feeling a thrill of admiration at the mysterious, yet, at the same time, strong and sweet ways of eternal Wisdom.
 The Liturgical Year, vol 12, p 478.