The new birth means that we are not reborn from a sinful person to a righteous person. It means that we are born from Adam into Jesus, which is to say from religion into life as sons of God. None of this is theoretical or merely propositional. It is real in that the being of God is incarnated in the being of you. It’s holistic. You become a manifestation of Christ not a clothes horse for bits of good character. You exhibit the fruit of the Spirit because you are no longer a tree of the knowledge of good and evil. You are a tree of life. Torrance explains it this way.
Christ your life means Christ expressing Himself as you.
“Sometimes, when Torrance talks about what he means by practical, it’s not what people are expecting. They’re expecting that theology has some additional task of making itself practical, showing itself relevant. When Torrance says theology is practical, he means that it’s inherently practical. When you’re talking about theology, you’re talking about the love of God incarnated in Jesus Christ, assuming our broken and diseased humanity. In assuming our broken and diseased humanity, God has established an utterly practical relation to us. God has taken on our very condition, our sin, our guilt, our alienation in order to overcome it. And so to say that theology is inherently practical is to say that God acts on our behalf in an absolutely concrete way.” (1) This is what Paul means by Christ our life.
His glory is seeing you come into your glory as a son/daughter of God.
The cross is never an end in itself. The cross is the beginning of the new and living way: The way to resurrection to your new creation life. The cross ends your life in Adam and propels you into your Jesus-life. In this life you are a son in spirit and in truth because Christ is alive in your flesh. He inhabits your body, soul and spirit.
(1) Anderson, Ray; Colyer, Elmer; Dawson, Gerrit; Deddo, Gary; Kettler, Christian; Kruger, Baxter; McKenna, John; McSwain, Jeff; Newell, Roger; Young, Paul. Trinitarian Conversations, Volume 1: Interviews With Ten Theologians (You're Included) (pp. 77-78). Kindle Edition.
The mystery of Godliness is not a form of piety but Jesus being you.