Refrain from these men - Cease to oppose them or to threaten them. The "reason" why he advised this he immediately adds, that if it were of human origin, it would come to nothing; if of God, they could not overthrow it.
This counsel or this work be of men - This plan or purpose. If the apostles had originated it for the purposes of imposture.
It will come to nought - Gamaliel "inferred" that from the two instances which he specified. They had been suppressed without the interference of the Sanhedrin; and he inferred that "this" would also die away if it was a human device. It will be remembered that this is the mere advice of Gamaliel, who was not inspired, and that this opinion should not be adduced to guide us, except as it was an instance of great shrewdness and prudence. It is doubtless right to oppose error in the proper way and with the proper temper, not with arms, or vituperation, or with the civil power, but with argument and kind entreaty. But the sentiment of Gamaliel is full of wisdom in regard to error. For:
(1) The very way to exalt error into notice, and to confirm people in it, is to oppose it in a harsh, authoritative, and unkind manner.
(2) Error, if left alone, will often die away itself. The interest of people in it will often cease as soon as it ceases to be opposed; and, having nothing to fan the flame, it will expire. It is not so with truth.
(3) in this respect the remark may be applied to the Christian religion. It has stood too long, and in too many circumstances of prosperity and adversity, to be of human origin. It has been subjected to all trials from its pretended friends and real foes; and it still lives as vigorous and flourishing as ever. Kingdoms have changed; empires have risen and fallen since Gamaliel spoke this; systems of opinion and belief have had their day, and expired; but the preservation of the Christian religion, unchanged through so many revolutions, and in so many fiery trials, shows that it is not of men, but of God. The argument for the divine origin of the Christian religion from its perpetuity is one that can be applied to no other system that has been, or that now exists. For Christianity has been opposed in every form. It confers no temporal conquests, and appeals to no base and strong native passions. The Muslim faith is supported by the sword and the state; paganism relies on the arm of the civil power and the terrors of superstition, and is sustained by all the corrupt passions of people; atheism and infidelity have been short-lived, varying in their forms, dying today, and tomorrow starting up in a new form; never organized, consolidated, or pure; and never tending to promote the peace or happiness of people. Christianity, without arms or human power, has lived, keeping on its steady and triumphant movement among people, regardless alike of the opposition of its foes, and of the treachery of its pretended friends. If the opinion of Gamaliel was just, it is from God; and the Jews particularly should regard as important an argument derived from the opinion of one of the wisest of their ancient rabbis.

Refrain from these men - Do not molest them, leave them to God; for if this counsel and work be of man it will come to nought, like the rebellion of Theudas, and that of Judas of Galilee: for whatever pretends to be done in the name of God, but is not of him, will have his curse and not his blessing. He whose name is prostituted by it will vindicate his injured honor, and avenge himself.

And now I say unto you, (n) Refrain from these men, and let them alone: for if this counsel or this work be of (o) men, it will come to nought:
(n) He dissuades his fellows from murdering the apostles, neither does he think it good to refer the matter to the Roman magistrate, for the Jews could endure nothing worse than to have the tyranny of the Romans confirmed.
(o) If it is counterfeit and devised.

And now I say unto you,.... This is the sum of my advice upon the observation of these and other instances:
refrain from these men, and let them alone; keep your hands off of them, do not attempt to take away their lives, but dismiss them quietly, nor go about to hinder them, in what they are concerned:
for if this counsel, or this work be of men; if the doctrine these men preach is an human device; or this business they are engaged in is only an human affair, projected by men, and carried on upon selfish principles, and worldly views, seeking only themselves, and their secular interests, and not the glory of God:
it will come to nought; as did the designs of Theudas and Judas.

if . . . of men, it will come to naught--This neutral policy was true wisdom, in the then temper of the council. But individual neutrality is hostility to Christ, as He Himself teaches (Luke 11:23).

Let them alone - In a cause which is manifestly good, we should immediately join. In a cause, on the other hand, which is manifestly evil, we should immediately oppose. But in a sudden, new, doubtful occurrence, this advice is eminently useful. If this counsel or this work - He seems to correct himself, as if it were some sudden work, rather than a counsel or design. And so it was. For the apostles had no counsel, plan, or design of their own; but were mere instruments in the hand of God, working just as he led them from day to day.