When one thinks of the Transfiguration one usually thinks of Christ being transfigured–almost like Christ turning on a light bulb. But there is a valid line of thinking in the Eastern Church that goes like this: “In a certain way it was really the apostles who were transfigured; it was they who became able to see.” It wasn’t so much Christ whose glory changed; the apostles were just allowed to see Him as He truly is. Christ opened their eyes so that they could see Him in all His glory.
And that’s the point of the Christian life, to have our eyes opened to the Mystery of God. To constantly surrender ourselves to His grace, that the eyes of our hearts may be transfigured and more and more able to perceive the beauty and glory of our God.