I have always been impressed with the thoughts (i.e. "Pensees") of Blaise Pascal (1623-1662). I am again reading his "Thoughts", and while they are not always accurate (he defended Jansenist doctrine), there are a lot of excellent comments made by him on a variety of topics (e.g. on the depravity of man). One of my favorite quotes ("Thoughts") of his comes from his first chapter, "Thoughts on Mind and on Style" #10:
"People are generally better persuaded by the reasons which they have themselves discovered than by those which have come into the mind of others."
In his chapter on "Morality and Doctrine", Pascal speaks very much like a Federal, Law/Gospel Calvinist:
"The law imposed what it did not give. Grace gives what it imposes." (522)
"All faith consists in Jesus Christ and in Adam, and all morality in lust and in grace." (523)
Perhaps my favorite quote is:
"Jesus Christ is a God whom we approach without pride, and before whom we humble ourselves without despair." (528)