Romans 12:3 : For I say, through the grace that was given me, to every man that is among you, not to think of himself more highly than he ought to think; but so to think as to think soberly, according as God bath dealt to each man a measure of faith. Paul speaks of his being made an apostle as the grace that was given him. The same thought is expressed in Romans 15:15-16 1 Corinthians 3:10; 1 Corinthians 15:10 Galatians 2:7-9; Ephesians 3:7. He warns Christians against thinking too highly of them-selves. To think soberly is to think sensibly--to think of our proper relations with God and our fellowmen. No one should feel himself to be wise above what is written, nor feel so important as to be domineering.
Neither should he, like Moses, feel that he is too insignificant to do what God commands him to do. "A measure of faith." It does not seem to me that "measure" here means portion. R. St. John Parry, in his notes in the Cambridge Greek Testament, says of the Greek term here translated "measure," "In N. T. it always has its proper significance of 'a measuring instrument.' "
Faith is the measuring instrument, the instrument by which we are to measure our thinking. Whether faith in this place refers to the gospel, as it does in some places, or to our own faith in the gospel, makes no difference for our faith includes a whole-hearted belief in the gospel. It equals the idea that the gospel is the measuring instrument; for our faith cannot go beyond the gospel, and should not fall short of it. Our faith is the gospel written in our hearts.