In stark contrast to the warning against being conformed to this world, Paul wrote in Romans 12:2 “be transformed by the renewing of your mind.”
This is for all those who are believers. We are all to be transformed by the renewing of our minds. As Paul addressed plural believers with the word “brothers,” so, here, the pronouns are plural. We are not to be conformed to the world, instead we are to be transformed by the renewing of our minds.
To the put the rubber to the road: Where is your mind? What do you dwell upon? What do you find yourself thinking about, desiring, wanting? If one ponders the Bible throughout the day, even the most mundane aspects of life can be accomplished with a renewed mind.
If you are one who consistently and constantly complains, stop (for that is not the will of God, according to Philippians 2:14), and be transformed by the renewal of your mind. If you are one who is constantly dwelling upon inappropriate fantasies, stop, and dwell upon those things that are true, and lovely, and pure, and of good report (as Philippians 4:8 commands). If you are one given to lies, stop (Colossians 3:9), and be transformed in the renewal of your mind by only dwelling on truth.