Moses wasn't exactly out looking for a job when God called him. Moses had gotten married and was tending the flock of his father-in-law Jethro when he saw burning bush. he went over to it and heard God say to him: "I am going to lead my people out of slavery, and I am sending you to the Pharaoh to tell him to release them, and you will lead them to a land flowing with milk and honey." Moses, in effect, told God he was happy to have been asked, and considered it an honor ... but he wasn't very good at public speaking, so maybe God should consider his brother, Aaron.
God told Moses that if he had a speech to give, he could ask Aaron to give it, but he wanted Moses to lead his people. Reluctantly, Moses accepted the call.
Jeremiah wasn't out looking for a call from God either. When the call came, Jeremiah told god that he was flattered to have been asked, but he was too young for a job like this and perhaps he might suggest someone older. God told Jeremiah that he had called him from his mother's womb to be his prophet.
St. Paul wasn't exactly looking for a prophetic role in the Christian community. he was out looking for Christians to haul to jail. but the Lord called him, and after much prayer, Paul accepted.
Despite his reluctance to take on that role.
- Little Blue Book, Diocese of Saginaw