Spurgeon's conversion as a teenager. Spurgeon's recollection of utter depravity prior to his conversion. The influence of his parents and grandparents ultimately led to his conversion. His critique of Roman Catholicism called, The Antichrist and Her Brood, written at 15 years of age, and more. 

Recommended Resources: 

• Spurgeon v. Hyper-Calvinism: The Battle for Gospel Preaching by Iain Murray 
• The Forgotten Spurgeon by Iain Murray 
• Spurgeon on the Christian Life: Alive in Christ by Michael Reeves 
• The Spurgeon Archive
• Phil Johnson's blog: Pyromaniacs