God, Be Merciful to Me, a Sinner!

I recently used Luke 18:13 to explain salvation in a nutshell to those attending a church membership class:

1. God—the ground of salvation, the one who does the saving work
2. Me—the subject in question, the one who needs rescue
3. Sin—the problem, the reason I need saving
4. Mercy—the means by which God acts savingly.