"'Skillful swimmers are not afraid to go above their depth, whereas young learners feel for the ground, and are loath to go far from the bank, Strong faith fears not when God carries the creature beyond the depth of reason. 'We know not what to do,' said good Jehoshaphat, 'but our eyes are upon Thee.'";Spurgeon's Sermon Notes
Further recommended reading & listening:
The Best of The Daily Spurgeon
The Forgotten Spurgeon, by Iain Murray
A Defense of Calvinism - by Charles Spurgeon