Luke says that the Spirit came down on the disciples at
Pentecost, after the Lord's ascension, with power to open the gates
of life to all nations and to make known to them the new covenant.
So it was that men of every language joined in singing one song of
praise to God, and scattered tribes, restored to unity by the
Spirit, were offered to the Father as the first fruits of all the
This was why the Lord had promised to send the Advocate: he was
to prepare us as an offering to God. Like dry flour, which cannot
become one lump of dough, one loaf of bread, without moisture, we
who are many could not become one in Christ Jesus without the water
that comes down from heaven. And like parched ground, which yields
no harvest unless it receives moisture, we who were once like a
waterless tree could never have lived and borne fruit without this
abundant rainfall from above. Through the baptism that liberates us
from change and decay we have become one in body; through the
Spirit we have become one in soul. … We need the dew of God.
Taken from the treatise Against Heresies by St.