Gandalf is one of the five Wizards that came to Middle-Earth during the Third Age. Most did not know where they came from or who they were. Olorin, Gandalf's true name, was a spirit from the Blessed Land, where the Powers of the world still lived. They had one mission and one mission only: thwart Sauron and bring peace to the peoples of Middle-Earth. Of the five, only Gandalf succeeded.
What we see in Gandalf is a powerful portrayal of Jesus' ministry on earth. Gandalf, is called the "Wisest of all the Istari" and people of all races look upon him as a teacher. He serves as the mediator between the Valar and the peoples of Middle-Earth. Not only that, he defeats that which all his peers could not resist: the power to dominate all others. More powerfully, he had the power to heal.
This is a vivid picture of Jesus the healer. No, Gandalf didn't walk all over Middle-Earth healing the sick but he did have compassion and he did have the power. Jesus was the wisest of men and even the scholars of his day called him "Teacher" - a title not easily gained from those in authority. In addition to this, Jesus serves as the only mediator between God and man - to atone for sin, not one of those sins belonging to him.
There are many other similarities between Tolkien's works and the Word of God. Why? Because your faith, if strong enough, affects all areas of your life, even fictional writing. Was Tolkien aware of this? Yes he was. In fact, he often remarked that when one has a strong belief in God, His truth appears in everything done. I encourage you to dig into the Word and see if you can find anything else. If you can, email me about it and explain your theory at [email protected].