The ancient and still-living tradition of Celtic Spirituality has been experiencing a renaissance in recent decades. As more and more of us seek spiritualities that honor the Sacredness of all creation, we're delighted to find this beautiful Celtic perspective as a guiding light. And so much the better that most of us already have a personal connection to it, even if we never realized it! By way of example – before diving into what this Celtic Tradition is – here's a bit on my connection to it:
I personally began studying the Celtic tradition as part of therapy and social justice work, where I was seeking to redeem the legacy of my ancestors in various ways. Like most white Americans, I can claim Celtic as one of my ancestral cultures – Celtic heritage (though not as my native culture – I can’t claim to be “a Celt”). And anyone can practice Celtic spirituality – this living tradition is open to all. As I discovered this for myself, I realized in many ways I’d already been walking the Celtic path my whole life.
This tradition still echoed in my family culture, in our music and art, waiting like a deep-buried wellspring to be found again. I saw its beauty could help heal intergenerational traumas, my own and others’, and it connected me more deeply with other ancestral traditions, gave me a context to stand in and something to offer – other than just my solo spirituality – in the struggle for a better world. This struggle entails prioritizing support for BIPOC folk in the healing of their intergenerational traumas, which, appallingly, have largely been inflicted by those of us with Celtic heritage. This struggle also entails inviting fellow white folk into the reckoning and reconciliation that comes with healing.
And I believe the best place to start from is inviting everyone into reconnection with the Celtic tradition. A huge reason we and our ancestors do and did such harm is because we’ve lost or forsaken our deep spirituality. By reclaiming it, we can take a huge step toward the world we were all made for.
So, what is this Celtic spirituality?
For starters, who were the Celts? Given their culture's appreciation for the mysteriousness of the world, it almost seems appropriate that they remain a mysterious people today.
We do know “Celts” are what the Romans called the conglomeration of all European peoples immediately north of their empire, lumping many disparate tribes from present-day Ireland to Romania under this catch-all term. We also know that at that time, many of these tribes had close commonalities in culture and spirituality, even if they were otherwise foreign to each other and would only have known themselves as “Celts” centuries before Rome existed. And we know that since the apogee of Roman and then Christian conquest, only Wales, Scotland, Ireland, the Isle of Man, Cornwall and Brittany have remained as intact outposts of ancestral Celtic tradition. These places were never as fully assimilated as lands closer to the Mediterranean, lying far enough out of reach to preserve some ancient Pagan heritage and syncretize it beautifully with Christianity. 
Despite all the mists of history, the Celts have left an indelible mark on Western culture and spirituality writ large, and their wisdom is helping reenchant our world now more than ever. What is this Celtic wisdom? In short: the preservation of our connection to the wisdom of Nature.
THE WISDOM OF NATURE
As with many ancestral peoples around the world, before being colonized the Celts lived in relative creative harmony with their environment. They reinforced this by practicing various forms and blends of:
pantheism – revering Nature as holy and holistically interconnected, often as a ubiquitous Mother Goddess
polytheism – ascribing anthropomorphic archetypal personalities to discrete aspects of Nature, society, and psychology as a way of understanding them
animism – seeing the world as imbued with magic and inhabited by spirits (such as faeries) living in a hidden dimension
These beliefs and associated rituals were transmitted within families and communities, but also by orders of specialized magician-practitioners. In the NAI (Northeast Atlantic islands), these practitioners are still known as:
Sadly, little information about these original practitioners or their rituals has survived to today, and even many of the spectacular remnants we have remain great mysteries. We do know however that these people recognized their magic, arts, sciences, and spiritualities – like humanity itself – as part of Nature. They recognized they were co-crafting civilization as an inseparable extension of the Earth, not somehow disunited from it. This nourished profound respect for the living world and humility regarding our place in it. 
In recent centuries, modern practitioners have begun reconstructing what traditions they can, and creatively improvising the rest. As a member of AODA, an association for such practitioners, I am engaging in this exciting work every day as a bard, ovate, and druid. We seek to cultivate an authentically-Celtic tradition as best we can, sharing in wisdom from other ancestral traditions (only) when it is offered. It's exciting to see uncanny convergences in this process, like the commonality among so many independent traditions to observe the importance of the “fours”: natural elements, cardinal directions, quartiles of the day, seasons of the year, and heavenly bodies orienting us – Sun, Moon, Stars/Planets, Earth. This shows that (while we must still be wary of cultural appropriation) all people can still find in Nature the echoes of a spiritual language, older and deeper than any single tradition known today.
Humanity needs to re-learn this spiritual language if we are to restore ecological wholeness and enter civilizational maturity. White folk need to learn this spiritual language from our own ancestors, if we are to stand in real solidarity with BIPOC folk and communities on the frontlines of environmental degradation – after all, they are the ones leading us toward wholeness and maturity. Further, allowing our over-rational minds to play with pantheism, polytheism, and animism a bit would do us all some good:
the Earth is indeed a holy and holistically-interconnected being, crying out for recognition as such
archetypes are some of the best tools for reminding us how intertwined we are with Nature, and for teaching us deep truths about ourselves
entertaining notions of faeries and such can draw our attention to the Sacredness of children, elders, animals, plants, and other living beings, which we too often relegate to “hiddenness.”
And we need bards, ovates, and druids now more than ever, sharing magic with the world.
As with many ancestral peoples around the planet, colonization robbed the Celts of much of their way of life. But they preserved what they could, often through syncretism, or blending of native traditions with others’, including those of the dispossessors. How does syncretism work? How did the Celts utilize it in their contact with Christianity?
In the meantime, I hope this article stirs some reflection questions for you:
How have you found connection to this Celtic perspective?
How have you been sharing magic with the world?
How have you been allowing your mind to play?
How have you been working for ecological wholeness?
How have you been expanding your spiritual language?
How have you been engaging tradition as a modern practitioner?
How have you been looking for or finding spiritual belonging?
How have you been working to heal intergenerational trauma, or redeeming your ancestors' legacy?
With any of these – how would you like to?
To learn more
 Edward C. Sellner, The Celtic Soul Friend: A Trusted Guide for Today (Ave Maria Press: 2002)
 John Michael Greer, The Druidry Handbook (Red Wheel/Weiser, LLC: 2006)