Why did John the Baptist begin to doubt or wonder about Jesus while in prison?
While imprisoned, John the Baptist heard of Christ's works and asked whether Jesus was the coming one or whether another should be expected. Although Jesus possessed power to free him from the authorities, He was not doing so, and from a human standpoint this caused John to wonder.
Les explains from Matthew chapter 11, verse 2, that when John the Baptist heard in prison the works of Christ, he sent two disciples to ask Jesus, “Art thou he that should come? Or do we look for another?” Les notes it is surprising that a man who fulfilled his ministry would question, but he did. John knew Jesus had power to simply take him out of the hands of the authorities and set him free, yet Jesus was not doing it. From the human standpoint, that is what John was beginning to wonder about.