{This} (houtos). Jesus the Son of God (verse  5 ). {He that
came} (ho elth(936e)). Second aorist active articular participle of
erchomai, referring to the Incarnation as a definite historic
event, the preexistent Son of God "sent from heaven to do God's
will" (Brooke). {By water and blood} (di' hudatos kai
haimatos). Accompanied by (dia used with the genitive both as
instrument and accompaniment, as in  Ga 5:13 ) water (as at the
baptism) and blood (as on the Cross). These two incidents in the
Incarnation are singled out because at the baptism Jesus was
formally set apart to his Messianic work by the coming of the
Holy Spirit upon him and by the Father's audible witness, and
because at the Cross his work reached its culmination ("It is
finished," Jesus said). There are other theories that do not
accord with the language and the facts. It is true that at the
Cross both water and blood came out of the side of Jesus when
pierced by the soldier, as John bore witness ( Joh 19:34 ), a
complete refutation of the Docetic denial of an actual human body
for Jesus and of the Cerinthian distinction between Jesus and
Christ. There is thus a threefold witness to the fact of the
Incarnation, but he repeats the twofold witness before giving the
third. The repetition of both preposition (en this time rather
than dia) and the article (	(9369) locative case) argues for two
separate events with particular emphasis on the blood ("not only"
ouk monon, "but" all') which the Gnostics made light of or
even denied. {It is the Spirit that beareth witness} (	o pneuma
estin to marturoun). Present active articular participle of
marture(935c) with article with both subject and predicate, and so
interchangeable as in  3:4 . The Holy Spirit is the third and the
chief witness at the baptism of Jesus and all through his
ministry. {Because} (hoti). Or declarative "that." Either makes
sense. In  Joh 15:26  Jesus spoke of "the Spirit of truth" (whose
characteristic is truth). Here John identifies the Spirit with
truth as Jesus said of himself ( Joh 14:6 ) without denying
personality for the Holy Spirit.