Monergism/synergism.
It's not that tough. Ask Rome. They understand. Everyone but the Reformed believe man must do something before you're saved.
God does the "before." We have enough to keep us busy with the "after."
Monergism/Synergism is a false issue.
Faith is not a work and thus cannot be viewed as adding anything to salvation.
The real issue is which comes first regeneration or faith, and the Bible says Faith.
As for keeping 'busy' after, what are you doing during your Christian walk.
Are you cooperating with God?
Is God controlling your every thought or are you resisting God when you refuse to yield?
Are you obeying God when you do yield?
Your progressive sanctification smacks of synergism (since you regard faith as a work)
The only alternative is that you are sinning because God will's that you sin and Rom.6:16-18 is just one of those 'facade' verses that is hiding the 'secret will' of God (as Calvin explained 2Pet.3:9 to be, and Spurgeon and Piper explained 1Tim.2:4 to be)