"From now on, therefore, we regard no one according to the flesh. Even though we once regarded Christ according to the flesh, we regard him thus no longer. If anyone is in Christ he is a new creation" (2Corinthians 5:16, 11).
Jesus and Paul were contemporaries and therefore Paul undoubtedly heard Jesus preach in the streets of Jerusalem. If so, he must have considered him to be an ignoramus from the back-country of Galilee.
But on the road to Damascus Paul experienced a radical change of heart: he saw Jesus as he really was, the son of God. From that point on, Paul did not evaluate Jesus by human criteria (“according to the flesh").
Viewing Jesus from that perspective also changed the way he looked at others: he no longer evaluated them according to the flesh, but as potentially in Christ and as radiant new creations.
Think of the worst person you know and imagine that person as an authentic follower of Jesus. What would that person be like if he or she was filled and flooded with God's Holy Spirit?
I wonder to what extent I judge others by merely human standards? What financial, physical, ethnic, educational and political criteria do I employ? Or do I view them as they could be if they would but give their hearts to Jesus? Can I think of the worst person I know in that way?
Speaking for myself, that would take a lot of prayer.