Verbal tradition passed down by order inhabitants claims that the first sermon was preached on Ardfernal Hill. (There is a large stone half-way along the ridge known as “The Prayer Stone”). Was the first preacher Earnan, the uncle of Columba? It is claimed that the name Ardfernal means “Earnan’s Hill”. Certainly St. Earnal is connected is closely connected with the early church on Jura for the original name of the “Parish of Kilearnadil” can be translated as “The Parish of Earnan in the dale (or valley)“.
Jura Parish Church – A Brief History (Gordon Wright)