A Pharisee and a "ruler of the Jews." He was part of the elite 70-member council that governed Jewish religious life. He was wealthy, respected, and educated.
Jesus called him "The Teacher of Israel" (John 3:10). He knew the Torah inside and out. He had all the answers, yet he came to Jesus because he sensed something was missing.
He was formed by Structure and Tradition. His life was defined by boundaries—what to eat, who to touch, when to pray. Jesus challenged him to be "born of the Spirit" (like wind), which has no boundaries.