In the homily of today’s office, Gregory says: “Love’s proof is in love’s work.”

But you say: we just aren’t able to fulfill the commands of God.

I say: you aren’t able to fulfill them by your own powers, but through the grace of God you certainly can do so!

Hence the Evangelist adds: “My Father will love him”—God shall not fail a man—“and we will come to him,” that is, we [the Father and the Son] will be present to him (Jn. 14:23).

By that presence, we will be able to dedicate our powers to fulfilling God’s commands.

Concerning this charity for fulfilling God’s commands, we read in Ephesians: “we are His workmanship, created in Christ Jesus in good works” (Eph. 2:10).

Where does this charity in us come from? The Holy Spirit.

“The charity of God is poured into our hearts by the Holy Spirit who is given to us” (Rom. 5:5).

He who has a share of daylight has that light from the sun; in the same way he who has charity has it from the Holy Spirit.

Therefore: “Send forth Thy Spirit, and they shall be created”—namely, in the being of the life of grace, through charity.

You see that men, when they become true lovers, make efforts to know the will of God.

“It belongs to friends to have one heart,” as it says in Proverbs, and God reveals His secrets to His friends.

And this is the second step of the creation which is from the Holy Spirit: that they[who are re-created may know God in wisdom.

[…] In today’s Gospel: “The Counsellor, the Holy Spirit, whom the Father will send in my name, he will teach you all things, and bring to your remembrance all that I have said to you” (Jn. 14:26).

Now, however much a man may be taught exteriorly, it will profit him nothing unless the grace of the Holy Spirit is interiorly present.

As the Gospel says, “The anointing will teach you concerning all things.”

And He not only teaches the truth, but will even call it back to mind.

It is as if Jesus were saying: “I myself am able to teach you, but you do not by this fact believe or want to fulfill what I teach.

“But He who brings it about that you believe and that you fulfill what you hear, He will call things back to mind.”

The Holy Spirit does this because he inclines the heart to give assent and to carry out what it hears.

Hence our Lord says: “Everyone who has heard and learned from my Father comes to me” (Jn. 6:45).

Thomas Aquinas (1225-1274): Sermon “Emitte Spiritum”.