A New Start and New Life
Unless one is “born again,” (undergo a spiritual transformation), he cannot “see” (perceive, understand deeper), the Kingdom of God." (John 3:3)
Jesus was confronting this leading Pharisee Nicodemus, with the truth that he needed a whole new heart — a new life; not just a cosmetic makeover or another ritual added to an already-oppressive system of spiritual disciplines.
He was telling Nicodemus that he would never be able to understand/perceive, (see) the kingdom unless there was a spiritual awakening of his dead soul.
A spiritual renewal so vast and dramatic that it can only be described as a second birth.
Jesus emphasized that spiritual rebirth is completely a work of God, not the result of human effort: “That which is born of the flesh is flesh, and that which is born of the Spirit is spirit” (John 3:6).
Jesus was merely stating a truth which, on reflection, ought to be self-evident.
Flesh produces flesh. Spirit produces spirit. Living beings all reproduce “after their kind” (Genesis 1:24).
By the very nature of things, therefore, spiritual life cannot be the fruit of human achievement.