If the “truth” that we believe does not set us free, then that “truth” is a lie. The Truth will set you free.
For one growing up in church, they could get the idea that sanctification is a process. That one becomes holier the closer he adheres to God's law and commandments now that they have received the free gift of salvation. However, righteousness is completely free! It is available to us through the finished work of Christ. It is all His doing. All His work! None of our own, lest we should boast. This is good news!