"Ready to open immediately when he comes and knocks"

Holy Gospel of Jesus Christ according to Saint Luke 12:35-38.

Gird your loins and light your lamps
and be like servants who await their master's return from a wedding, ready to open immediately when he comes and knocks.
Blessed are those servants whom the master finds vigilant on his arrival. Amen, I say to you, he will gird himself, have them recline at table, and proceed to wait on them.
And should he come in the second or third watch and find them prepared in this way, blessed are those servants.

Commentary of the day
Saint Ambrose (c.340-397), Bishop of Milan and Doctor of the Church
12th Sermon on Psalm 118 ; CSEL 62, 258

"Ready to open immediately when he comes and knocks"

God, the Word, stirs up the lazy and arouses the sleeper. For indeed, someone who comes knocking at the door is always wanting to come in. But it depends on us if he does not always enter or always remain. May your door be open to him who comes; open your soul, enlarge your spiritual capacities, that you may discover the riches of simplicity, the treasures of peace and sweetness of grace. Expand your heart; run to meet the sun of that eternal light that «enlightens everyone» (Jn 1,9). It is certain that this true light shines for all, but if anyone shuts their windows then they themselves shut themselves off from this eternal light.

So even Christ remains outside if you shut the door of your soul. It is true that he could enter but he doesn't want to use force, he doesn't put those who refuse under pressure. Descended from the Virgin, born from her womb, he shines throughout the universe to give light to all. Those who long to receive the light that shines with an everlasting brightness open up to him. No night comes to intervene. Indeed, the sun we see each day gives way to night's darkness; but the Sun of justice (Mal 3,20) knows no setting for Wisdom is not overcome by evil.