"Studied expressions and high notions in a sermon are like Asahel's carcass in the way, that did only stop men and make them gaze, but did no ways profit them or better them. It is better to present truth in her native plainness than to hang her ears with counterfeit pearls." - Thomas Brooks, as quoted in 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