If you want to see Luther’s lesser known list of theses, click here. Let’s keep pondering their value for us as preachers:
Theses 13-15 – Luther goes on to underline the propensity to evil found in natural condition humanity. He even questions whether genuine love is possible, certainly with respect to God. So the will is free only in the sense that it will conform to erroneous and incorrect teaching. Within that realm, the will appears free because the dictator within lives in that darkness. How often do preachers pile on the pressure when the listeners are incapable of responding with better morality – they may shift their actions, but will continue to be in that earthly realm that is totally other than God’s goodness.
16. One ought rather to conclude: since erring man is able to love the creature it is impossible for him to love God.
While we may not be familiar with the juxtaposition Luther gives here, it shouldn’t be unfamiliar to us. Think of Jesus’ words, that it is not possible to serve two masters, you will either love one and hate the other, or serve the one and despise the other. Perhaps we need to ponder the mutual exclusivity of affection when we preach to people (since our tendency is to be “both/and” in our thinking).
17. Man is by nature unable to want God to be God. Indeed, he himself wants to be God, and does not want God to be God.
I hope you didn’t leave before this one! This is vitally important. Humans do not want God to be God, but we consistently vote for another candidate – ourselves. The influence of the Lie in Genesis 3 is so pervasive we can easily miss it, like the water the goldfish is swimming in. So as preachers, are we trying to encourage morality and goodness without addressing the real issue? I can convince people to help older folk across the road, but superficial morality in no way addresses the core “me for president of the universe” political inclination of the human heart (and we all know presidential candidates like to be seen to do good!)
18. To love God above all things by nature is a fictitious term, a chimera, as it were. This is contrary to common teaching.
So the great commandment is impossible for a fallen humanity. People will not love God, so what do we do? Do we command it? Or do we prayerfully present the self-revelation of God’s heart in His Word, pointing to the Word incarnate, and invite people to look to Him? More on this to come . . .
Biblical Preaching 
“Perhaps we need to ponder the mutual exclusivity of affection when we preach to people (since our tendency is to be “both/and” in our thinking).”
That doesn’t sound right — how can you square it with 1 John 4:20? “Whoever claims to love God yet hates a brother or sister is a liar. For whoever does not love their brother and sister, whom they have seen, cannot love God, whom they have not seen.”
Hi Mike – Luther is setting up the mutually exclusive options that I cite from Jesus, that is, that we cannot “serve two masters.” 1 John is describing the overflow of a love relationship established with God, i.e. if we are responsively loving God then that love will flow to others too. He will write later on in the 97 about how an unbeliever can appear to do well, but such “goodness” is always corrupted. Good stuff to ponder!