I am going to stumble for words here and in the next few posts. Because the New Covenant in Jesus, of the Holy Spirit, is far more mighty, marvellous, weighty, shining, hope-saturated, spine-tingling and just magnificently beautiful than the language I have to describe it. "Glory" is probably the word that comes closest, but even that fails because Paul says that this rates with the most glorious things. Some things are glorious - but then there is this. We are in a whole different ballpark. On another planet. Experiencing a different order of magnitude. So I will just see if I can enthuse as much as I can. Picture me being as thrilled by it as a person can be thrilled. I hope you are too.

Paul starts referring to this new covenant (new agreement between God and people contrasted with the old covenant Mosaic Law) in ch 2, by showing the effect that it has on the lives of people who are drawn into it - they become a fragrant perfume, presented by Jesus to the Father. That's what the new covenant does. But what is it about it that creates such a potent fragrance? Here is how 2 Cor 4 answers:

The new covenant reveals... the light of the gospel of the glory of Christ who is the image of God v4

The new covenant dawns when... God, who said "let light shine out of darkness" has shone in our hearts to give us the light of the knowledge of the glory of God in the face of Jesus Christ v6

Just compare those two a minute. See the connection: the knowledge of the glory of God = the gospel of the glory of Christ. If you want to have light (true understanding) on the glory of God, you get it "in the face of Jesus Christ", who is the image of God, through grasping the good news of his glory.

That is the fundamental ground for discipleship. We grow as Christians by following the light of the gospel of the glory of Christ. It is also the, properly understood, the fundamental ground of all theology (which is merely discipleship seeking right understanding of God's revelation). Anything that claims to be theology, or proper religion or seeking understanding of matters to do with God that doesn't ground itself here is at best seriously deficient (and more likely fatally, foundationally flawed).

"The light of the knowledge of the glory of God in the face of Christ" is the most important thing you can possibly get in this life or the next. It is the pursuit that is worth our whole lives. It is the thing we should most want to base every aspect of our lives upon. Christians are new covenant people, alive to God in Christ and indwelt by the Holy Spirit. We should expect to see real-world application and outworking of this in our characters, actions, every day experience and future hope.