The dynamics of personal transformation in 2 Corinthians 3:18 assume that we are changed into what we admire and fix our attention on. ‘Beholding the glory of the Lord, [we] are being transformed into the same image.’ We know this is so from experience. Long looking with admiration produces change. From your heroes you pick up mannerisms and phrases and tones of voice and facial expressions and habits and demeanors and convictions and beliefs. The more admirable the hero is and the more intense your admiration is, the more profound will be your transformation. In the case of Jesus, he is infinitely admirable, and our admiration rises to the most absolute worship. Therefore, when we behold him as we should, the change is profound. Of course, there is more to it than that. The reflexes of imitation are not the whole story of how we change. Part of what we pick up in looking at Jesus in the gospel is a way of viewing the whole world. That worldview informs all our values and deeply shapes our thinking and decision-making. Another part of what we absorb is greater confidence in Jesus’ counsel and his promises. this has its own powerful effect on what we fear and desire and choose. Another part of what we take up from beholding the glory of Christ is greater delight in his fellowship and deeper longing to see him in heaven. This has its own liberating effect from the temptations of this world. All these have their own peculiar way of changing us into the likeness of Christ. Therefore, we should not think that pursuing likeness to Christ has no other components than just looking at Jesus. Looking at Jesus produces holiness along many different paths.
– John Piper from God is the Gospel