"The god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the image of God." (2 Corinthians 4:4-6).

"The “glory of Christ” is the beauty of Christ. It is the radiance of the fullness of his person—the impact of all his perfections. The reason people do not believe on Christ is that they do not see what is really there. That is what it means to be “blind.” Beauty is really there to be seen, but we are blind to it.

If we see it, we believe. “Beauty is irresistible.” If you resist, you have not seen Christ as beautiful as he is (1 John 3:6b). So the way we are converted to Christ is by having this blindness taken away. Verse 6 says, “God has shone in our hearts to give the light of the knowledge of the glory of God in the face of Jesus Christ.” God replaces blindness with light. The light is specifically “the glory of God in the face of Christ.”

That is all it takes. There is no coercion after that revelation. The light compels. We don’t behold it and then ponder whether to believe. If we are still pondering, we have not yet seen." - John Piper