for the same
reason that the day when Mary "brought forth her first-born son" we name
"the birthday of Jesus Christ." Yet Jesus had existed before he lay in
the cradle at Bethlehem; he was "in the beginning with God"; he was the
agent in creation. By him all things were. But on the day of his birth
he became incarnate, that in the flesh he might fulfill his great {20}
ministry as the Apostle and High Priest of our confession, manifesting
God to men, and making himself an offering for the sins of the world.
Not until after his birth in Bethlehem was Jesus in the world in his
official capacity, in his divine ministry as mediator between man and
God; and so not till after the day of Pentecost was the Holy Spirit in
the world in his official sphere, as mediator between men and Christ. In
the following senses then is Augustine's saying true, which calls
Pentecost "the birthday of the Spirit":

1. The Holy Spirit, from that time on, took up his residence on earth.
The Christian church throughout all this dispensation is the home of the
Spirit as truly as heaven, during this same period, is the home of Jesus
Christ. This is according to that sublime word of Jesus, called by one
"the highest promise which can be made to man": "If a man love me he will
keep my words: and my Father will love him, and we will come unto him,
_and make our abode with him_" (John 14: 23). This promise was fulfilled
at Pentecost, and the first two Persons of the Godhead now hold residence
in the church through the Third. The Holy Spirit during the present time
is in office on earth; and all spiritual presence and divine communion of
the Trinity with men are through him. In other words, while the Father
and the Son are visibly and personally in heaven, they are invisibly here
in the {21} body of the faithful by the indwelling of the Comforter. So
that though we affirm that on the day of Pentecost the Holy Spirit came
to dwell upon earth for this entire dispensation, we do not imply that he
thereby ceased to be in heaven. Not with God, as with finite man, does
arrival in one place necessitate withdrawal from another. Jesus uttered
a saying concerning himself so mysterious and seemingly contradictory
that many attempts have been made to explain away its literal and obvious
meaning: "And no man hath ascended up to heaven but _he that came down
from heaven, even the Son of man who is in heaven_"--Christ on earth, and
yet in glory; here and there