Great Sermon!
The good fruit of the sermon of the late pastor, Dr. Kennedy, is still fresh, and the message of grace is timeless.
Regarding indulgences, Psalm 49:6-8 KJV comes to mind.
"They that trust in their wealth, and boast themselves in the multitude of their riches; None of them can by any means redeem his brother, nor give to God a ransom for him: (For the redemption of their soul is precious, and it ceaseth for ever:) That he should still live for ever, and not see corruption."