oath aright, let us imitate the seriousness and the reverent manner exhibited by the Apostles; and
that you may understand what it is, know that God is so called as a witness, that he is also appealed
to as an avenger, in case we deceive; which Paul expresses elsewhere in these words,
“God is a witness to my soul.” (2 Corinthians 1:23.)^30
Whom I serve with my spirit,etc. It is usual with profane men, who trifle with God, to pretend
his name, no less boldly than presumptuously; but the Apostle here speaks of his own piety, in
order to gain credit; and those, in whom the fear of God and reverence for his name prevail, will
dread to swear falsely. At the same time, he sets his own spirit in opposition to the outward mask
of religion; for as many falsely pretend to be the worshippers of God, and outwardly appear to be
so, he testifies that he, from the heart served, God.^31 It may be also that he alluded to the ancient
ceremonies, in which alone the Jews thought the worship of God consisted. He then intimates, that
though he retained not observance of these, he was yet a sincere worshipper of God, according to
what he says in Philippians 3:3,
“We are the true circumcision, who in spirit serve God,
and glory not in the flesh.”
He then glories that he served God with sincere devotion of heart, which is true religion and
approved worship.
But it was expedient, as I have said, in order that his oath might attain more credit, that Paul
should declare his piety towards God; for perjury is a sport to the ungodly, while the pious dread
it more than a thousand deaths; inasmuch as it cannot be, but that where there is a real fear of God,
there must be also a reverence for his name. It is then the same thing, as though Paul had said, that
he knew how much sacredness and sincerity belonged to an oath, and that he did not rashly appeal
to God as a witness, as the profane are wont to do. And thus, by his own example, he teaches us,
that whenever we swear, we ought to give such evidence of piety, that the name of God, which we
use in our declarations, may retain its sacredness. And further, he gives a proof, even by his own
ministry, that he worshipped not God feignedly; for it was the fullest evidence, that he was a man
devoted to God’s glory, when he denied himself, and hesitated not to undergo all the hardships of
reproach, poverty, and hatred, and even the peril of death, in advancing the kingdom of God.^32
Some take this clause, as though Paul intended to recommend that worship which he said he
rendered to God, on this account, — because it corresponded with what the gospel prescribes. It is
indeed certain that spiritual worship is enjoined on us in the gospel; but the former interpretation
is far the most suitable, — that he devoted his service to God in preaching the gospel. He, however,
makes at the same time a difference between himself and hypocrites, who have something else in
view rather than to serve God; for ambition, or some such thing, influences most men; and it is far
from being the case, that all engage cordially and faithfully in this office. The meaning is, that Paul
performed sincerely the office of teaching; for what he says of his own devotion he applies to this
subject.
(^30) The passage in Matthew 5:33-37, has been often wholly misunderstood. That oaths in common conversation are alone
prohibited, is quite evident from what the passage itself contains. In solemn oaths there was no swearing by “heaven,” or by
“God’s throne,” or by “the earth,” or by “Jerusalem,” or by “the head.” such forms were only used in conversation, as similar
ones are still used: and these kinds of swearing are alone condemned by our Savior. — Ed.
(^31) “Sincerè et verè — sincerely and truly,” Wolfius, “not merely externally, but cordially,” Hodge.
(^32) “by the preaching of the gospel, etc.” Stuart. “In predicando evangelio — in preaching the gospel,”
Beza. “I serve God, not in teaching legal rites, but a much more celestial doctrine,” Grotius