Homily – 20 December O Key of David — God Opens What We Cannot

From this evening the Church will cry out:

O Key of David.

A key does one thing.
It opens.

And that is exactly what today’s readings are about:
God opening what humanity cannot open for itself.

In the first reading, King Ahaz is afraid.
Enemies surround him.
The future feels unstable.

God offers him reassurance: “Ask the Lord your God for a sign.”

But Ahaz refuses.

He sounds religious:
“I will not test the Lord.”

But it is not humility.
It is resistance.

Ahaz does not want God to intervene.
He wants control.

So God gives a sign anyway: “The virgin shall conceive and bear a son.”

This is crucial.

Salvation does not depend on human willingness alone.
God acts first.
Grace opens the door.

Then we turn to Nazareth.

A young woman.
An ordinary home.
No power.
No influence.

The angel greets Mary and announces the impossible.

And Mary asks a question —
not in disbelief,
but in trust seeking understanding.

“How can this be?”

And then comes the decisive moment.

Mary says: “Let it be done to me according to your word.”

This is where the door opens fully.

God offers salvation freely.
But He waits for consent.

Mary does not unlock salvation by her power.
She allows God to unlock it through her.

The O Antiphon puts words to what we are seeing:

“O Key of David and sceptre of the house of Israel,
You open and no one can shut;
You shut and no one can open.”

Christ is the Key.

He opens the door between heaven and earth.
He opens the door of forgiveness.
He opens the door of eternal life.

No human strength can force these doors open.
No human sin can slam them shut beyond His reach.

That is why Advent ends here — not with effort, but with surrender.

There is a pattern in today’s readings.

Ahaz refuses a sign.
Mary receives one.

One keeps the door closed through fear.
The other opens it through trust.

This matters.

God wants to save us.
He has the key.
But He does not break the door down.

He knocks.

Salvation is not imposed.
It is welcomed.

Mary shows us the posture of Advent faith:
openness, trust, obedience.

As Christmas draws near,
the question is simple and personal:

What doors am I keeping closed to God?

Fear.
Control.
Sin we refuse to surrender.

Christ comes holding the key.
Not to accuse,
but to open.

But He waits for our yes.

Today the Church prays with confidence:

O Key of David, come.

Open what is locked in us.
Unlock forgiveness.
Unlock hope.
Unlock salvation.

And like Mary,
may we say with our lives:

“Let it be done to me according to your word.”