Thus both act in the desire to please the Lord, and for the Lord. "The God of all knows the intention of those who eat and those who do not eat. He does not look at the deed alone, but tests the understanding with which it is done" (Blessed Theodoret). Therefore He receives both.
God receives him, but you condemn him. With what is this consistent? What do you make yourself out to be?
"He who eats, eats to the Lord, for he gives thanks to God." By thanking God for giving food for enjoyment, for the satisfying of hunger, and for the support of life, he shows that he eats to the glory of God, for the Lord. Since he thanks God when receiving food, he eats to the Lord.
"And he who does not eat, does not eat to the Lord, and gives thanks to God." He thanks God for giving him strength to abstain and to offer Him this sacrifice of self-denial. Eating becomes eating for the Lord through thanksgiving. Not eating is directly for the Lord, and has thanksgiving as its consequence, adornment, and sanctification.
Chrysostom says: "The meaning of the Apostle's words is that the importance does not lie in eating or not eating. The question is whether both do it for God, and whether both end with thanksgiving. According to the Apostle's words, both thank God. If they thank God, the difference is not great."
Photius, in Oecumenius, writes similarly: "The one who eats thanks God for receiving food, because God gave food for satisfaction and the support of life. The one who does not eat thanks God because He gave men abstinence and endurance as help in overcoming fleshly passions.
"But in some other sense, the one who eats or fasts is subject to condemnation, as certain heretics are. The Apostle's words must be understood in relation to those who fast and eat in a God-pleasing way, and in no other way.
"This cannot be said of all, but only of those who act in both cases as they should. Therefore these words are no longer entirely fitting for the one spoken of before, namely the one who distinguishes foods in a Jewish spirit.
"Such a man also does not eat, but he does not refrain from eating to Christ's glory. He does so as one weak and not established in the faith. Yet even he must not be condemned, because of the circumstances of the time, since the preaching was then only beginning.
"But the one who eats every day with thanksgiving, and the one who fasts for whole days, or more than a day, according to abstinence, must not be condemned at all. Both do what they do to the glory of the Lord."
Saint Paul affirmatively says that both the one who distinguishes days and the one who does not distinguish them do this for the Lord. Yet he knew that it was possible to do either not for the Lord. He likewise affirmatively says that the one who eats and the one who does not eat do this for the Lord and thank God. Yet he knew that in both of them either one might be absent.
Why, then, did he speak so? He spoke in order to remind them that, when acting in this way, they must act precisely in this spirit. He also gave us a lesson not to judge them otherwise than in a good sense.
Since we cannot know what is in their heart, but know that they must act in all things for the Lord and give thanks to God for all things, and since they took this obligation upon themselves, we have no ground to think they do not act so. Having no ground, we cannot judge them. To condemn them would be slander.