Sean (written "Seán" or "Séan" in Irish) is a Hibernization of the English name "John"; that is, it's a transliteration of "John" into a form which can be pronounced in Irish and written with the Irish alphabet (which nowadays is simply a version of the Roman alphabet).
There were references to the origin of the above idiom, my favorite (supported here as well) being from the movie, The Untouchables, wherein Sean Connery utters with contempt, "Isn't that just like a [racist for Italian]... brings a knife to a gun fight."
I've noticed many Scottish and Irish Gaelic words to be spelled with an s, followed by a vowel, and pronounced like sh. Think about the way Sean Connery speaks (not to mention how the Se in his name is pronounced).
The archangel Michael battles wicked angels and wages war with the Devil. Is Jesus himself the archangel Michael? The Bible reveals the answer.
Who Is Michael the Archangel? Is Jesus? | Bible Teach - JW.ORG
Michael was called “the prince of [Daniel’s] people,” “the great prince who is standing in behalf of the sons of [Daniel’s] people.” (Da 10:13, 20, 21; 12:1) This points to Michael as the angel who led the Israelites through the wilderness.
Michael, o němž někteří mluví jako o „svatém Michaelovi“, je jméno, které měl Ježíš předtím a potom, co žil na zemi. Proč je takový závěr logický?
Der Name Michael – in manchen Religionen auch „Heiliger Michael“ genannt – bezeichnet Jesus, und zwar bevor er auf der Erde lebte und danach. Gibt es dafür Beweise?