Romans 14:13

Let us not therefore judge one another any more: but judge ye this rather, that no man put a stumbling block in his brother's way, or an occasion of falling.

Paul here included himself, not as a confession of guilt in the matter of the judgments he was condemning, but in order to make a more delicate and persuasive appeal to his readers (just as he doubtless did in Hebrews 2:1-3); but, as noted by Lenski,

Exhortations against wrong are in place for all of us, if for no other reason, then at least that we may keep on avoiding wrong.[12]

Lenski also has a very dramatic translation of this verse, thus:

But rather make this your judgment not to place a stumbling block or a deathtrap for your brother.

In this, and to the end of the chapter, Paul spoke of the proper use of Christian liberty. Having shown that it is sinful to judge fellow Christians concerning things immaterial and unessential, he proceeded to show how the governing principle in such forbearance is that of love for men who are beneficiaries of the blood of Christ, who have been redeemed from sin and made to stand in the body of Christ himself.

It is no trivial matter to cause a brother to stumble. The "falling" here means falling from God's grace, falling away from the eternal inheritance, and falling so as to be lost eternally. Such consequence as this can follow the contemptuous "setting at naught" of a weak brother, in which case the disaster recoils in damnation upon the head of the "strong" offender, involving both in ruin. "Setting at naught" is a dangerous and deadly sin.