Let us not therefore judge - Since we are to give account of ourselves at the same tribunal; since we must be there on the same "level," let us not suppose that we have a right here to sit in judgment on our fellow-Christians.
But judge this rather - If disposed to "judge," let us be employed in a better kind of judging; let us come "to a determination" not to injure the cause of Christ. This is an instance of the happy "turn" which the apostle would give to a discussion. Some people have an irresistible propensity to sit in judgment, to pronounce opinions. Let them make good use of that. It will be well to exercise it on what can do no injury, and which may turn to good account. Instead of forming a judgment about "others," let the man form a determination about his own conduct.
That no man - A "stumbling-block" literally means anything laid in a man's path, over which he may fall. In the Scriptures, however, the word is used commonly in a figurative sense to denote anything which shall cause him to "sin," as sin is often represented by "falling;" see the note at Matthew 5:29. And the passage means that we should resolve to act so as not "by any means" to be the occasion of leading our brethren into sin, either by our example, or by a severe and harsh judgment, provoking them to anger, or exciting jealousies, and envyings, and suspicions. No better rule than this could be given to promote peace. If every Christian, instead of judging his brethren severely, would resolve that "he" would so live as to promote peace, and so as not to lead others into sin, it would tend more, perhaps, than any other thing to advance the harmony and purity of the church of Christ.

Let us not, therefore, judge one another any more - Let us abandon such rash conduct; it is dangerous, it is uncharitable: judgment belongs to the Lord, and he will condemn those only who should not be acquitted.
That no man put a stumbling block - Let both the converted Jew and Gentile consider that they should labor to promote each other's spiritual interests, and not be a means of hindering each other in their Christian course; or of causing them to abandon the Gospel, on which, and not on questions of rites and ceremonies, the salvation of their soul depends.

(12) Let us not therefore judge one another any more: but judge (m) this rather, that no man put a stumblingblock or an occasion to fall in [his] brother's way.
(12) After he has concluded what is not to be done, he shows what is to be done: that is, we must take heed that we do not utterly abuse our liberty and cast down our brother who is not yet strong.
(m) He rebukes along the way these malicious judgers of others who occupy their heads about nothing, but to find fault with their brethren's life, whereas they should rather focus their minds upon this, that they do not with disdainfulness either cast their brethren completely down, or give them any offence.

Let us not therefore judge one another more,.... With respect to the observance or non-observance of the laws relating to meats and drinks, and days, and times; the apostle means, that they should not judge rashly, nor anything before the time; they should not censure and judge each other's characters and states, on account of these things, but leave all to the decisive day, to Christ the Judge, and to his bar, before which all must stand:
but judge this rather; or reckon this to be the most proper, fit, and advisable:
that no man put a stumblingblock or occasion to fall in his brother's way; as in the former part of the advice the apostle seems to have respect more especially to the weak brethren, who were ready to judge and condemn such as neglected the observance of the laws about meats and days, as transgressors, and as wicked persons, that ought not to be in the communion of the church; so in this he seems more principally to have regard to the stronger brethren; who, through their imprudent use of their Christian liberty, offended weaker minds, and were the occasion of their stumbling and falling, which it became them to be careful to prevent; and rather than be a means of anything of this nature, it was much better, as he afterwards observes, neither to eat flesh, nor drink wine, and entirely drop or forego the use of their liberty.

Let us not therefore judge--"assume the office of judge over"
one another; but judge this rather, &c.--a beautiful sort of play upon the word "judge," meaning, "But let this be your judgment, not to put a stumbling-block," &c.

But judge this rather - Concerning ourselves. Not to lay a stumblingblock - By moving him to do as thou doest, though against his conscience. Or a scandal - Moving him to hate or judge thee.