John Calvin Commentary Romans 14:3

"Let not him that eateth set at nought him that eateth not; and let not him that eateth not judge him that eateth: for God hath received him." — Romans 14:3 (ASV)

Let not him who eats, etc. He wisely and suitably meets the faults of both parties.

Those who were strong had this fault—they despised as superstitious those who were scrupulous about insignificant things and also derided them. These, on the other hand, could hardly refrain from rash judgments, so as not to condemn what they did not follow, for whatever they perceived to be contrary to their own sentiments, they thought was evil.

Therefore, he exhorts the former to refrain from contempt and the latter from excessive moroseness. And the reason he adds, since it belongs to both parties, ought to be applied to these two instructions: “When you see,” he says, “a person illuminated with the knowledge of God, you have evidence enough that he is received by the Lord; if you either despise or condemn him, you reject him whom God has embraced.”