"Justin Martyr was asked ironically by the Roman prefect if he believed that after his decapitation he would ascend into heaven. He replied: 'I am so sure of the grace which Jesus Christ hath obtained for me that not a shadow of a doubt can enter my mind." From 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