God can use anybody to fulfill his will.God uses the despised and foolish, so that no one can boast.
1 Corinthians 1:27-29

27 But God chose the foolish things of the world to shame the wise; God chose the weak things of the world to shame the strong. 
28 God chose the lowly things of this world and the despised things—and the things that are not to nullify the things that are, 
29 so that no one may boast before him

God can not be mocked,God can not be taken for granted.
No one ,I repeat no one is indispensable.
We are all instruments in the hand of God , chosen and designed for his glory ,his will and his pleasure.

Our wisdom and understanding is still and will always be subject to God's will.
When men try to assume God's role and position ,he many times without number humbled them.

In all that you do , always remember God ,for he has the whole world in his hand.He has the final say.