For God who commanded the light to shine out of darkness, has shined in our hearts. To give the light of the knowledge of the glory of God in the face of Jesus Christ.
But we have this treasure in earthen vessels, that the excellency of the power may be of God and not of us. 2 Corinthians 4: 6-7
Just like our great and mighty Creator God spoke the first light into existence ( “Let there be light”), so he shines the light of the glory of his gospel into our hearts. One way or another, he gets his light in there. We didn’t know God, and wouldn’t have recognized him even if we had seen him. It’s like he had his back to us, like he did with Moses when God told him he could see his “back parts”, but not his face, or he would die from seeing all that glory. (Ezekiel 33)
Then God turned around and let us see him in the face of Jesus. We recognize people by their faces. God gave us Jesus so we could recognize him. He turned around so we could see his face and know who he is. All of Gods goodness and mercy and grace is represented in Jesus, so that we can know our God. If we have seen Jesus, we have seen God. If we know Jesus, we know God.
He gave us this knowledge ( a valuable treasure) housed within our earthly bodies ( imperfect earthen vessels) so that we can give the good news to others, God can be glorified, and his power known and experienced.
When we have seen Jesus, we can show him to others.