I recently posted some golden nugget quotes from Charles Haddon Spurgeon on faith. Here's another.
Spurgeon, once answered the question, “What is faith?” this way:
“Now what is faith? In one word, it is trust—the trusting of the soul in God’s promise made in Christ Jesus. My faith is that which enables me to believe that God is true, to believe that he sent his Son in the flesh to suffer for my sins; to believe that, through the merit of his blood and the virtue of his holy life, I am saved. To trust in him to save me—this is faith.”
--C. H. Spurgeon, The Metropolitan Tabernacle Pulpit Sermons, Vol. LXI (London: Passmore & Alabaster, 1915) 176.