"Man cannot be saved by perfect obedience, for he cannot render it; he cannot be saved by imperfect obedience, for God will not accept it."(Source: Spurgeon's Sermon Notes)
Recommended reading:
The Conversion of Charles Spurgeon
The Forgotten Spurgeon, by Iain Murray
A Defense of Calvinism - by Charles Spurgeon
The Forgotten Spurgeon, by Iain Murray
A Defense of Calvinism - by Charles Spurgeon
You can also listen to an audio recording of The Forgotten Spurgeon on Sermonaudio.com: