Bernard of Clairvaux

Bernard of Clairvaux is an interesting person from history. Luther and Calvin both claimed him for the Reformation (though he lived in the 1100s), and of course the Roman Catholic Church claimed him for themselves as well. He was from the era of knights. His father was a knight, and his mother a 'lady.' Here are three things that stood out in an article on him in a little book called the 5 Minute Church Historian by Dr. Rick Cornish:

He pictured the stages of spiritual development as degrees of love for God.

He wrote that the purpose of study and meditation on Scripture is not to gather information but to reform the fallen divine image within and thus draw us closer to God.

He did not teach a pantheistic merger with God's nature, as some later monks did, but rather a unity of our will and God's.

As I write this I havn't looked, but it might be worth searching for a good biography of him and his approach to the faith in general...