3 For I say, through the grace given unto me, to every man that is among you, not to think of himself more highly than he ought to think; but to think soberly, according as God hath dealt to every man the measure of faith.
4 For as we have many members in one body, and all members have not the same office:
5 So we, being many, are one body in Christ, and every one members one of another.
6 Having then gifts differing according to the grace that is given to us, whether prophecy, let us prophesy according to the proportion of faith;
Once upon a time, the animals decided they should do something meaningful to meet the problems of the new world. So they organized a school.
They adopted an activity curriculum of running, climbing, swimming and flying. To make it easier to administer the curriculum, all the animals took all the subjects.
The duck was excellent in swimming; in fact, better than his instructor. But he made only passing grades in flying, and was very poor in running. Since he was slow in running, he had to drop swimming and stay after school to practice running. This caused his web feet to be badly worn, so that he [became] only average in swimming. But average was quite acceptable, so nobody worried about that — except the duck.
The rabbit started at the top of his class in running, but developed a nervous twitch in his leg muscles because of so much make-up work in swimming.
The squirrel was excellent in climbing, but he encountered constant frustration in flying class because his teacher made him start from the ground up instead of from the treetop down. He developed "charley horses" from overexertion, and so only got a C in climbing and a D in running.
The eagle was a problem child and was severely disciplined for being a non-conformist. In climbing classes he beat all the others to the top of the tree, but insisted on using his own way to get there. . . .
The point of the story is obvious. Like the animals, every person has his own special but limited set of capabilities. Trying to operate outside those capabilities produces frustration, discouragement, guilt feelings, mediocrity, and ultimate defeat. We fulfill our calling when we function according to God's sovereign design for us.
(from The MacArthur New Testament Commentary, Copyright © Moody Press and John MacArthur, Jr., 1983-2005.)