Now there are varieties of gifts, but the same Spirit; and there are varieties of services, but the same Lord; and there are varieties of activities, but it is the same God who activates all of them in everyone. To each is given the manifestation of the Spirit for the common good. (1 Corinthians 12:4-7)
In the first chapter of The Hobbit, while taking advantage of Bilbo Baggins' hospitality, the dwarves begin to discuss their strategy for reaching the Lonely Mountain and vanquishing the dragon. Thorin describes a possible route that will take them up to the front gates of the dwarves' former stronghold, but Gandalf quickly nixes that idea:
"That would be no good," said the wizard, "not without a mighty Warrior, even a Hero. I tried to find one, but warriors are busy fighting one another in distant lands, and in this neighbourhood heroes are scarce, or simply not to be found. Swords in these parts are mostly blunt, and axes are used for trees, and shields as cradles or dish covers; and dragons are comfortably far-off (and therefore legendary). That is why I settled on burglary – especially when I remembered the existence of a side-door. And here is our little Bilbo Baggins, the burglar, the chosen and selected burglar."
The dwarves have a job that needs doing, and they trust Gandalf to find the right man for that job. When he can't find the warrior or hero to lead them to Smaug's front door, he finds an even better solution: a burglar to help them get in the side door that he has just found out about.
God has given everyone gifts that allow them to do a certain job. When the task at hand requires someone to bring compassion and care to people in need, he calls the healer. When someone is needed to teach others about his love, he calls the teacher. When he knows that there are many who need to hear his word, he calls the preacher. Whatever the task, someone has been given the ability to take care of it – even when the person best-suited is not the one we had in mind to begin with. Fortunately, though, when someone with vision and foresight and the ability to think creatively is needed to recognize this, God calls that person, too.