When God calls you to do something, it means two things:  He knows you have the capability to do it and secondly it means you will be called to a higher level of accountability.  Jesus said in Luke 12:48, "Unto whom much is given, of him much shall be required".

We are accountable to God even if we refuse to submit and be accountable to man.  A humble attitude is something we must always maintain if we are to remain pliable and useful in the hands of God.  A calling of God on your life does not mean you are not cut from the same bolt of cloth as others.  You must be careful to make the distinction between the treasure and the vessel.  If you are a leader, never allow anyone to expect you to be the treasure.  Keep your ego in check, be real and stay humble.  "We have this treasure"...we are not the treasure.  We are only clay jars holding the treasure.

God does specialize in using clay jars to reflect the treasure He's placed inside of it.  He even uses broken vessels...people we wouldn't use.  He used a prostitute to help win the battle of Jericho and then included her in the family of Christ.  What about Jephthah?  He was a young man born to an unwed mother and rejected by his family.  He lived in caves, was the leader of a mercenary gang that terrorized people.  God used him to deliver Israel and become the nation's youngest judge.

What am I trying to say?  If you don't stay humble before God He can pick anybody to replace you.  It is a privilege to work for God.  See it that way and stay humble!