"David was vexed with rival gods, as we are with rival gospels. Nothing is more trying to the soul of a true man than to be surrounded with vile counterfeits, and to hear these cried up, and the truth treated with contempt.'" - 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