Check out T. M. Moore's recent Crosfigell article "A Terror to the Devil" -- the story of how St. Columba's contemporaries viewed him (and a challenge to us to become like him). Here's an excerpt:

How did Columba get that way? He loved God and hated his own sin. He pored over the Word of God, giving special attention to the Law and the Gospels. He spent long hours praying and contemplating the unseen realm ... [and] he was a diligent student of Church history, knowing the debt he owed to the martyrs and theologians of the past.

(Image courtesy of Wikipedia)