The Apostle Paul
Romans 12:3ESV·traditional attribution

For by the grace given to me I say to everyone among you not to think of himself more highly than he ought to think, but to think with sober judgment, each according to the measure of faith that God has assigned.

John Calvin Reformed @genevareformer

3. For I say, through the grace, etc. If you think not the causal particle superfluous, this verse will not be unsuitably connected with the former; for since he wished that our whole study should be employed in investigating the will of God, the next thing to this was, to draw us away from vain curiosity.

Matthew Henry Presbyterian @wholebiblehenry

We may observe here, according to the scheme mentioned in the contents, the apostle's exhortations, I. Concerning our duty to God, We see what is godliness. 1. It is to surrender ourselves to God, and so to lay a good foundation. We must first give our own selves unto the Lord, Co2 8:5. This is here pressed as the spring of all duty and obedience, Rom 12:1, Rom 12:2.

Commenting on Romans 12:1-21

John Gill Reformed Baptist @doctorgill

For I say, through the grace given unto me,.... The Ethiopic version reads, the grace of God: and so two of Stephens's copies. By which the apostle intends, not that internal grace which was wrought in his soul; nor the Gospel of the grace of God, which he preached; nor the gifts of grace, which qualified him for that service; but the grace of apostleship...