I have been listening to Thomas Merton's lectures, Ways of Prayer: A Desert Father's Wisdom, on the Conferences of Saint John Cassian. Good stuff and lots of humor. I had heard these cassettes forty years ago at Osage Monastery; their quality was poor and I found it hard to listen for long although I enjoyed them. This new remastered version is much better! The sound levels are much improved.
One thing that caught my ear was Merton's second lecture on Saint John Cassian's writing on how to pray, focusing on the Pater Nostra. Then, of course, what is the next petition? "Fiat voluntas tua". Well that calls for a whole--incidentally, where is this in Tertullian? There it is, he's got it back here. For some reason Tertullian has "Fiat voluntas tua" in front of "Adveniat regnum tuum". He's just being original, or what? Actually, he's got some very good things on this "Fiat voluntas tua". And, what he gets down to is, obviously, what we all get down to sooner or later with "Fiat" is the question of accepting suffering. But Tertullian says, the word of God is done praedicando, operando, sustinendo--by preaching, by working, by suffering. So, praedicando, you can change that for confitendo confessio, bearing witness to the truth of the Gospel, which we do where--in choir, at least, and we do a chapter, occasionally, and we do it there. Operando--by our works and virtue and so forth. And then sustinendo, which is a significant word, it isn't just patienendo but sustinendo. What's the difference between patienendo and sustinedo, Brother Basil? . . . Persevering and bearing it, you see, accepting it. You can suffer without accepting it. Sometimes we suffer and we don't want to suffer and we have to suffer anyway and there is nothing we can do about it. But sustinendo means accepting it and bearing with it; courage, bravery, and so forth. And so, he says, when we say "Fiat voluntas tua", he is saying we have to think this may mean the acceptance of suffering and we should accept suffering and we should accept, well, the frustration of our desires and of all these things which are implied in the idea of suffering. And we have to accept that, to realize, of course, what goes with that, is the realization that whatever God wills for us is best, even though at the moment it may contradict our desires, nevertheless in the long run it is best, in the long run it does lead to salvation although it may take us off the road for the moment.
Kinda reminds me of the "Fiat" in the Annunciation, "The word “fiat” means an official decree or to give sanction to something. In Latin it means “let there be” or “let it happen/exist." I never connected the "fiat" of the "Our Father" with the "Fiat" of Mary or, even, the "Fiat" of Jesus in the Garden of Gesthemene ("non mea voluntas sed tua fiat" Luke 22:42). I believe this is one of the distinctive aspects of Christianity, that when we pray "thy will be done", when we are praying the "Fiat", we are accepting the suffering that comes from doing God's will. This contrasts Christianity significantly with the Stoics and the Epicureans in regard to suffering, that we embrace the suffering that is part of the package deal of "thy will be done".