"Faith is a living and unshakeable confidence, a belief in the grace of God so assured that a man would die a thousand deaths for its sake. This kind of confidence in God's grace, this sort of knowledge of it,. makes us joyful, high-spirited, and eager in our relations with God and will all mankind. That is what the Holy Spirit effects through faith."
-- Martin Luther

(Can't forget the old school dudes like Martin Luther who laid the foundations of our faith through preaching and teaching! This quote taken from Martin Luther: Selections from His Writings.)