In Romans 14, we have the spirit in which Christians should behave towards one another. There are those who are weak in faith, not fully in the light and power of new creation. They love the Lord; they have been purchased by Christ’s precious blood. but like a Jew they observe days and diet. That is weakness. So we are to receiving such in grace, not doing anything which could unsettle their faith. If the heart is pure, no meats are defiled meats – ‘To the pure all things are pure’ (v.20) . But if a person defiles his conscience, even through an unfounded scruple to him, it is unclean. If somebody normally felt he should regard a certain day, or abstain from a certain food, but does not in order to feign liberty, that is sin – it is not of faith .
Each stands or falls to his own Master, and God is able to make both the weak and the strong stand. Every one is to be fully persuaded in his own mind, not acting on another’s faith. Each is responsible to the Lord and must look to Him. We are to be peaceful edifying others.
The Christian should not put a stumbling-block in his brother’s way. It is uncharitable to lead a weaker brother to violate his conscience – that would drive him away from Christ, as if Christ made the one for whom He died lawless. We should not despise the weak brother or sister because of the scruples which they would not have, if they understood deliverance. Conversely, the weak person should not judge the strong, charging him with evil because of his freedom. God will be the Judge. ‘Every one of us shall give account of himself to God’ (v.12).
Romans 15:1-7 belong to chapter 14. The strong are to bear the infirmities of the weak, and, like Christ, not to please themselves. He meekly bore the reproaches that fell on Him, walking so faithfully and perfectly that, when men were disposed to reproach God, the reproach fell on Christ. ‘The reproaches of them that reproached thee fell on me’ (v. 3, Ps 69:9). The Old Testament scriptures were written for our instruction, so that we might know that God’s mind. Our reproach is His reproach, as we serve and have part with Him in faith and confidence. It is the path of love, serving others for Christ’s sake. But God is patient, bearing with our stupid, ignorant, and often inconsistent hearts. He occupies Himself with all our little trials to comfort us in grace. So have we receive one another as Christ received us – weak in faith – that we might be here to the glory of God. This closes the exhortations of the epistle.
A simplified summary of part of the introduction to John Nelson Darby’s Exposition of the Epistle to the Romans