The Apostle Paul
Romans 14:18ESV·traditional attribution

Whoever thus serves Christ is acceptable to God and approved by men.

John Calvin Reformed @genevareformer

18. For he who in these things, etc. An argument drawn from the effect: for it is impossible, but that when any one is acceptable to God and approved by men, the kingdom of God fully prevails and flourishes in him: he, who with a quiet and peaceful conscience serves Christ in righteousness, renders himself approved by men as well as by God.

Matthew Henry Presbyterian @wholebiblehenry

We have in this chapter, I. An account of the unhappy contention which had broken out in the Christian church. Our Master had foretold that offences would come; and, it seems, so they did, for want of that wisdom and love which would have prevented discord, and kept up union among them. 1.

Commenting on Romans 14:1-23

John Gill Reformed Baptist @doctorgill

Let us therefore follow after the things, Since the kingdom of God is in part peace, and the man that serves Christ in this, as in other things, is accepted with God, and grateful to men, the apostle very pertinently exhorts to seek after such things, which make for peace: not with God, for, for a sinful creature to make peace with God is impracticable...