ESV - 2 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.
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
We who are born-again are "aliens... in this world" (1 Pet 2:11 AMP), the unregenerate being the "natives" (1 Pet 2:11 MSG). We are not "only human" or "just forgiven"; we are new creatures (2 Cor. 5:17).
"I implore you," Peter says (1 Pet 2:11) - " I beseech you," Paul says (Rom 12:1) - to change your thinking about yourselves: from being merely human to being "partakers of the divine nature" (2 Pet 1:4 KJV).
To do this (and if you do this you will find yourselves rejoicing in the Lord always, "with joy unspeakable and full of glory," 1 Pet 1:8 KJV), Paul says to concentrate your thinking on this ONE thing: "THE thing which is good and acceptable and perfect" (Rom 12:2 AMP, caps mine) that God has both willed and done "for you" and "in you" out of His good pleasure (Phil 2:13 KJV). If you are born-again, that holy thing that was conceived in you by the Word of God (11 Pet 1:23, p. Luke 1:35 KJV) is your glorified spirit.