St Patrick preaching the Trinity "I arise today Through a mighty strength, the invocation of the Trinity, Through the belief in the threeness, Through confession of the oneness Of the Creator of Creation." – from the poem known as St Patrick's Breastplate. Detail from a window in Holy Trinity church, in Stratford-upon-Avon.
Patrick, patron saint of Ireland, is known for spreading Christianity throughout Ireland in the century. Although not at the same level as Christmas and Easter, St. Patrick’s day is a religious day, and I’m glad I understand it as such.