"I am unworthy because I filthily adhere to the mire of dung and all my good deeds are like a rag used by a ...."

Wow.
That metaphor of self-abasement, in a prayer, no less!
Just wow.
Fr Hunwicke has a interesting post about so-called "Celtic Christian spirituality.

Historians have decisively abandoned the concept of the 'Celtic', and especially of a supposedly distinctive 'Celtic Church'. In the most recent major scholarly work on this subject, Professor Charles-Edwards' Early Christian Ireland (Cambridge, 2000), the distinguished author writes dismissively of 'that entity - beloved of modern sectarians and romantics but unknown to the early Middle Ages - "the Celtic Church"', and surveys in a footnote the scholarly work of the last thirty years which has established this.

It interests me because I have a sister who has an affinity for such folderol and the lack of sense in some of the stuff she comes out with boggles the mind.
A flat, declarative statement often contradicts the immediately preceding flat, declarative sentence, but she is blessedly free from anxieties about logic.
My family, in general is given to riffing on matters about which we know very little, creating "facts" out of thin air just to see the reaction we provoke. It's simply good fun if it's just us, but others are often disturbed by what seems like mêlées, but is really jousting with blunt weapons.
Not that combatants don't sometimes sustain injuries even so - the problem being, someone who suddenly decides to go for blood, (this is rare,) or someone who is eager to dish it out but who feigns a genuine wound when she receives the same blow from a weapon recently wielded by her, that everyone else laughed off. (The feminine pronoun is deliberate, and is not a reference to the Irish Lass mentioned above.)
This occurs, or used, with unfortunate frequency, but the problem has been solved by not letting anyone as delicate as she join in any reindeer games.

Really, isn't this an absurd family dynamic for a woman in late middle-age such as myself to own?

Anyway, back to the nonsense-spouting, Celtishness-claiming sister above - what is delightful about her malarkey is that she doesn't mind being called on it, not a bit, she doesn't even defend or backtrack or deny - she just ignores it and smilingly moves on to the next fantasy or hogwash.
But this, of Fr Hunwicke's, so nails her -

my only quarrel is with people who simply manufacture stuff themselves, sometimes of an in-tune-with-nature or down-with-Roman-dogma-and-legalism type, and slyly claim that it is 'in the Celtic Spirit'.

In point of fact, I don't think she does manufacture any of it, I think she parrots and synthesizes from books given her by, and conversations held in front of her by, her pub and fiddle and knotwork buddies.
With many of them, who remember people who remembered people who remembered Easter and the Post Office, though they'd like to engage in the traditional hobby, the existence of the Republic has put a damper on that,  so "I think I'll go and join me comrades and talk a little treason" has been replaced by "I think I'll go and join me comrades and talk a little heresy."

I'm looking forward to our next visit, and tales of oaks and Druids and the Dagda and Ossian and Crones syncretized into Saints and Magick and beehives.
No, really!