As a child is born physically with a mind, arms, and legs, he or she must learn how to use them.
They do not become practical without trial and error.
We too must work out change from our born again Spirit to transform our thoughts and habits into practical actions.
That’s why Paul said things like this.
“I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God, which is your spiritual worship.
Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect (Romans 12:1-2 ESV).
We don't work for our salvation, but we do work it out by continually yielding to God the use of our bodies (hands, feet, eyes, and ears), and transform our thoughts by what God says about us in His word about our present born again state.
M. H. Dennis