Romans 14:1-12 has been used to sanction a variety of behaviours. It’s admonition ‘not to judge’ and its categorization of believers into those with weaker and stronger faith—represented specifically in their eating habits—has, I fear, led to more confusion than help. Many have used this passage to break the law, rather than fulfill it. (See chapters 12 and 13 for the fulfillment.)
If we take Romans as a whole, it is clear that the primary conflict in the early church was between Jewish and Gentile believers; one people, of the Law, chosen; another people, pagan, also now chosen. Both of them now under the same God. That’s what Paul is saying when he quotes Isaiah 45—that God’s global plan of salvation, through which every knee will bow and tongue confess—has happened, and the fact that we see Jews and Gentiles together in church bending knee and confessing Christ is a sign of that. Now, having confessed, we point to Christ as our judge. It is to Him that we must give account for our actions and choices, for what we eat, and what we do not eat. And eating here isn’t really the point—eating is a kind of crib for the Law. That is why there are weaker and stronger brothers in faith. Those who are stronger are free to fulfill the law; those who are weak are still depending on the law. And thus Paul’s advice falls into focus: our primary business in the meantime is not to dispute, but to walk together. If my faith allows me to eat what the law condemns, then glory to God. If my faith, in weakness, does not allow this, then I must leave judgment to God. To the brother who can eat, patience toward the weak. To the brother who cannot eat, hold back the judgment. In all things, love one another, because this fulfills the law.