The following numbered items are common assumptions made by synergists in rejecting the bondage of the will and God's sovereign grace in salvation.
Fallacy #1. God would not command us to do what we cannot do.
God gave the Law to Moses, The Ten Commandments, to reveal what man cannot do, not what he can do.
A. Premise #1 is unscriptural. God gave the Law for two reasons: To expose sin and to increase it so man would have no excuse for declaring his own righteousness. Why? Because in the context, he does NO righteousness. As Martin Luther said to Erasmus, "when you are finished with all your commands and exhortations from the Old Testament, I'll write Ro.3:20 over the top of it all." Why use commands and exhortations from the O.T. to show free will when they were given to prove man's sinfulness? They exist to show what we cannot do rather than what we can do. Yes, God gave commands to man which man cannot do. Therefore commandments and exhortations do not prove free will. Nowhere in scripture is there any hint that God gives commands to natural men to prove they are able to perform them.
[Here is the passage Luther quoted to Erasmus to show that law's purpose is to expose our bondage to sin, not show our moral ability to keep it: "Now we know that whatever the law says it speaks to those who are under the law, so that every mouth may be stopped, and the whole world may be held accountable to God. For by works of the law no human being will be justified in his sight, since through the law comes knowledge of sin." Rom 3:19, 20]