The One Doctrine We Best Not Get Wrong
We look back on our justification and we look forward to our glorification, but where we all live is in the realm of sanctification. This is one doctrine that needs major clarification.
You can't afford to not understand sanctification. It's an internal, supernatural, sovereign work of the Holy Spirit whereby God wants us to behold his glory as He transforms us, using His enabling power and our cooperative effort.
According to Philippians chapter 2 verses 12 and 13, God's part is to work in us to will and do His good pleasure. Our part is to work out our salvation with fear and trembling. To mine the gold God has put there. To walk in the victory Christ purchased for us.
If you're going to grow in Christ then these things to be present… God's word and prayer, reliance on the Holy Spirit, obedience to God, and worship of God.