How each of us connects with the divine is what I, personally, call spirituality.
The Irish were converted to Christianity without benefit of an army. They retained within their spirituality many of their pre-Christian traditions: a respect for woman, a love of nature, and an appreciation for the interconnected web of all life. They believed that life was about choice, and the consequences of these choices.
The pre-Christian educated class among the Celts was the Druids. They were the lawyers, doctors, scholars, clergy, and bards of their time. Mention of them comes down to us in the stories and sagas of the people.
Celtic is pronounced "keltic", not "seltic." . The slide into Christianity was a short trip from an Old Religion that provided many faces to the same deity and a tradition of sacrifice by male leaders. The Celtic Christian spiritual path, with its emphasis on the Incarnation of Christ present in daily life, became the bedrock of all English Spirituality.