Listen to how the God brought this old servant to the Lord in prayer.
"But one morning, when I was again at prayer, and trembling under the fear of this [Whether the blood of Christ was sufficient to save my soul], that no word of God could help me. That piece of a sentence darted in upon me, "My grace is sufficient." At this methought I felt some stay, as if there might be hopes. But, oh, how good a thing it is for God to send his Word! For about a fortnight before I was looking on this very place, and then I thought it could not come near my soul with comfort, therefore I threw down my book in a pet (a sulking in an upset childish manner). Then I thought it [God's grace] was not large enough; but now, it was as if it had arms of grace so wide that it could not only enclose me, but many more besides."
- Extracted from Grace Abounding to the Chief of Sinners by John Bunyan, section 204.