People have always used everyday objects or experiences to explain spiritual truths. To take that which is seen to help example what is unseen. When Patrick arrived in Ireland from Britain in the late 5th century, legend has it that he used the shamrock to educate the Irish about the trinity.
The trinity is the theological concept describing the profound mystery that: 1) there is one God 2) who exists eternally as three distinct persons, known as God the Father, God the Son and God the Spirit, and 3) each person is fully God.
It’s a big concept that Patrick found helpful to begin to explain to people who had never heard the gospel using a little plant God scattered all over Ireland.
All is well,