Seldom in church evangelism has any missionary been blessed with a more fruitful ministry.
St. Patrick did indeed help to rid Ireland of 'snakes', but it was that 'Serpent of old', the devil:
Revelation 12:9 "And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world."
Captured by Celtic raiders in the 4th century, God called Patrick to return to the spiritually dark land where he was once a slave, in order to take the gospel of Christ to the people of Ireland.
The preaching of Patrick was used by Almighty God to transform many of the Irish people from idol worshiping pagans into servants of the Lord Jesus Christ.
God empowered him to overcome powerful Druid occult leaders, bloodthirsty tribal chieftains, and a host of other dangers to help set the people of Ireland free through the message of Salvation.
See more about St. Patrick HERE and HERE.