When Zechariah saw him, he was terrified; and fear overwhelmed him. But the angel said to him, “Do not be afraid, Zechariah, for your prayer has been heard. Your wife Elizabeth will bear you a son, and you will name him John. You will have joy and gladness, and many will rejoice at his birth, for he will be great in the sight of the Lord. He must never drink wine or strong drink; even before his birth he will be filled with the Holy Spirit.
—Luke 1.12-15
When Elizabeth heard Mary’s greeting, the child leaped in her womb. And Elizabeth was filled with the Holy Spirit and exclaimed with a loud cry, “Blessed are you among women, and blessed is the fruit of your womb. And why has this happened to me, that the mother of my Lord comes to me? For as soon as I heard the sound of your greeting, the child in my womb leaped for joy. And blessed is she who believed that there would be a fulfillment of what was spoken to her by the Lord.”
–vv.41-45
The angel’s prophecy might be a foreshadow of John’s leaping in Jesus’ presence before he is born. If that’s the case, then being “filled with the Holy Spirit” being overjoyed in the presence of God. This is surely a theme throughout the Gospel and Acts: who has the Holy spirit and what that causes in those people, namely joy.
Secondly, this is such a beautiful passage and an evidence that children can experience spiritual things before their born. David says elsewhere that he loved God even while in the womb. This should (hopefully) mess with the heads of those that deny the place on infant baptism in God’s Church.