I glean my lessons in v.32 reading thus:

And I, if and when I am lifted up from the earth [on the cross], will draw all people to Myself [Gentiles, as well as Jews].”

All we need to do is continually present/lift up the cross of the Lord when we continually live the crucified life and as well. When we allow Galatians 2: 20 to be fulfilled in our lives, God will draw men to Himself by the testimonies they see in us as we life up Christ.