It has been said the Patrick used the shamrock as a symbol to teach the doctrine of the Trinity to unbelievers. He would say "Is it one leaf or three?" "It is both one leaf and three," was their reply. He would teach that God is One God in Three Persons. "Go ye therefore, and teach all nations, baptizing them in the Name of the Father, and of the Son, and of the Holy Ghost" (Matthew 28:19).