Although the Hobbit, Bilbo Baggins, is undoubtedly the main character in the novel as it is after all named after him, Gandalf, the wizard has proven to be the most interesting. The main reason that this has come about is because of the mystery involved in Gandalf. And this has been set up through not only Gandalf’s tendency to disappear to places unknown to the travelers, but also by Tolkien who has purposely told very little about the wizard and his past.
One of the things that makes him so interesting is his great knowledge which has made for some seemingly odd decisions that have yet to have been explained. The example that best shows this is the one that he made at the very start of the novel when he came to the door of a lonely, but happy hobbit who he elected to take on a hard, dangerous adventure… something he knew Bilbo was not interested in at the very least. While his reasoning behind selecting this hobbit instead of any other hero or even a slightly adventurous person has been justified in that Bilbo is small and quiet and quite simply makes for fourteen members on the expedenture (one more than unlucky thirteen), there also seems to be something else, perhaps something that only Gandalf knows about Bilbo (including Bilbo himself). And he hints at this fact by repeatedly referring to Bilbo as a good "burglar" even though Bilbo has yet to prove this in any way by being caught every time he goes to burgle. However, one logical reason for Gandalf bringing Bilbo along (although Gandalf couldn’t have known this would happen at the start) is that he must know the hobbit has found an enchanted ring, and knows it will some day do them all great good. And although it is somewhat of a stretch, perhaps Gandalf, by calling Bilbo a burglar, knew that he would, at one time or the other, come up with something such as the enchanted ring, and thus be beneficial.
Another main issue that has come up to this point in the novel concerning Gandalf has been the influence he has had on the fourteen others on the adventure. While the most obvious of these has been the many times he has disappeared only to reappear and save them at the last possible moment, just his presence has done wonders for their confidence in themselves and confidence in their outcome being a good one. Of course, this has come to be based on the great reputation Gandalf has accumulated throughout his years, and it shows on each and every one of the travelers. An example of this is the constant moaning that was going on upon news that they and Gandalf would part ways at the entrance of Mirkwood Forest. They know (they believe actually) that Gandalf can and will get them out of terrible situations and so without him they feel very vulnerable to all of there surroundings. Their actions have also shown to become less focused in the absence of Gandalf as each time he has left them they have ended up losing their wits and falling off their original course, a trend that will undoubtedly continue unless someone such as Bilbo or Thorin steps up to assume the role of the leader.
Thus, Gandalf has shown to be, although he does it in a mysterious manner, as positive of an influence on the group as they could hope for. However, on the down side of this fact, his influence can only be positive when he is present to the dwarves and hobbit, meaning that without him, for the time being, they are quite hopeless.