During the Sunday "children's sermon," a pastor gathered the little ones around him and told this story. On a breezy March day, the town mayor happened through the park where a small boy was flying the largest, most beautiful kite he had ever seen. I soared so high and floated so gently, the mayor was sure it must be visible from the next town. Since his little town did not have very many thing of note to its credit, the mayor decided to award a "key to the city" to the one responsible for setting the spectacle aloft.
"Who is responsible for flying this kite?," the mayor inquired.
"I am," said a boy. "I made the kite with my own hands. I painted all the beautiful pictures and constructed it with scraps I found in my father's workshop. I fly the kite," he declared. 
"I am, " said the wind. "It is my whim the keeps it aloft and sets the direction it will go. Unless I blow, the kite will not fly at all. I fly the kite," the wind cooed.
"Not so," exclaimed the kite's tail. "I make it sail and give it stability against the wind's whims. Without me, the kite would spin out of control and not even the boy could save it from crashing to the earth. I fly the kite," declared the tail.
"Now, who flies the kite," the pastor asked. "They all do," said several kids in concert. SMART KIDS! It takes everyone doing their part to fly a kite. Same in the body of Christ! Let's all do our part!

Romans 12:4 says, "Just as each of us as one body with many members, and these members do not all have the same function."