It was a double secret in fact.
One part of the secret was about who he really was. The angel had said, “son of the Most High”, “son of God”. But in what sense? The title was clear but the meaning wasn’t. It took his whole life to give people an idea what it meant - actually his life and death and resurrection. And even then it was hard to put into words. It wasn’t just that he was like God in certain ways. It was also that God himself was making himself known in Jesus. It was not just that people got a glimpse of a reflection of God, it was as though God himself was looking out at them through the eyes of Jesus, as if God himself was speaking when they listened to Jesus.
The other part of the secret was about the meaning of his name – Jesus, Saviour. Lots of people had opinions as to how they wanted God to rescue them (just as people do now). Although the scriptures already described how God would rescue his people, it wasn’t finally clear until Jesus was raised from the dead. So before he rescued them, Jesus gave them clues that they would recognise later and help them understand what his death was for. And what his name meant.
The secret is now an open secret. It tells us something new about God. The one God has shown himself in human flesh and personally rescued his people from death. And the noise and fuss has still not died down.
Dale