Proportion of faith

(Rom. 12:6). Paul says here that each one was to exercise his
gift of prophecy, i.e., of teaching, "according to the
proportion of faith." The meaning is, that the utterances of the
"prophet" were not to fluctuate according to his own impulses or
independent thoughts, but were to be adjusted to the truth
revealed to him as a beliver, i.e., were to be in accordance
with it.

In post-Reformation times this phrase was used as meaning that
all Scripture was to be interpreted with reference to all other
Scripture, i.e., that no words or expressions were to be
isolated or interpreted in a way contrary to its general
teaching. This was also called the "analogy of faith."