"So we have stopped evaluating others from a human point of view. At one time we thought of Christ merely from a human point of view. How differently we know him now! This means that anyone who belongs to Christ has become a new person. The old life is gone; a new life has begun!"
"Paul emphasizes spiritual judgment and spiritual insight into people’s lives and situations. Our experience of Christ’s love moves us to stop viewing others according to worldly standards and to learn how to view them from the standpoint of God’s great act of salvation in Jesus Christ. When Christ was regarded from a worldly point of view, men rejected and crucified Him as a blasphemer and troublemaker. But from the divine viewpoint, Christ is the Messiah and Son of God, in whom the new creation and reconciliation with God is given."
Resource: The footnote for verse 16 in The Life Application Study Bible.