God came into the world as a human.  He came as one of us taking up our cause and making it his own.  In doing this, he makes known his glory. John says we saw his glory as the one full of grace and truth.  In one very special moment, John saw the shining forth of transcendent splendour as Jesus was transfigured on a mountain.  But as John moved constantly with Jesus he saw his glory in the lowly self-giving of the man for others.  So we see no division between what God does for us and our salvation and what he does to show his glory. It is through his grace expressed towards us in self-giving love that we see his glory.  

Moses once prayed, “Lord show me your glory”.  In response, the Lord revealed himself to Moses as The Lord, the Lord, the compassionate and gracious God, slow to anger, abounding in love and faithfulness… (Exodus 34: 6).  In Jesus, John sees this same glory expressed in the lowly self-giving of the man for others.

Did God need to display his glory in the world?  I suppose God could have enjoyed his self-knowledge within his own Triune communion of joyful love. Nevertheless, he wanted to come to us showing his glory as the one full of grace and truth.  And now, God shines his light into our dark hearts so that we might see the light of the knowledge of the glory of God in the face of Jesus Christ. Yes, the God of Grace, shows his glory personally to us in the face of Jesus as the Spirit enables us to gaze on his glory.