"I asked a young friend, 'Did you pray before conversion?' She answered that she did after a sort. I then inquired 'What is the difference between your present prayers and those before you knew the Lord?' Her answer was, 'Then I said my prayers, but now I mean them. Then I said the prayers which other people taught me, but now I find them in my heart."(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: