Without giving away too much of the story, let me just say that Merlin later has an opportunity to speak one on one with the Master of Miracles, who urges the great magician to forsake his magic. Merlin is confused by this admonition since he is certain that God is the creator and giver of all things, including his magic. Additionally, he is unsure how his magic differs from the "magic" that Christ used to heal the sick and raise the dead. When he poses these questions to Jesus, he soon learns a valuable lesson about magic and every other gift from God. I would like to share with you the gist of Christ's response:
For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him: - Colossians 1:16
Every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning. - James 1:17
Merlin was correct in his thinking. According to the verses above, God is the creator of all things, and it is God who bestows on man gifts and talents. So, why would God give a gift, then condemn the use of that gift? Simply put, it is God who gives the gift, but man is the one who uses and misuses those gifts. Just as with salvation, God gives man a choice. He does not force us to do things, but He guides us and encourages us to do right and to live by His Word.
But this is where Merlin really grows confused because he intends to only use his magic for good. There is no evil intent in his heart. Just a Jesus healed and helped, so does Merlin want to do the same. Still, Jesus cautions him against the use of magic. Why? Because with that gift must come wisdom. Jesus didn't heal everyone when He could have healed them all with a single breath or batting of the eye. But he didn't. He didn't even free his own cousin from prison when He certainly had the power to do so. Even though He possessed all power, He refrained from using it in certain ways and on certain people. Why? In order to fulfill His Father's plan.
You see, unlike Merlin, Jesus knew and understood the Father's plan and could, therefore, act according to that plan. What Merlin didn't yet understand is that his intentions to do good could interfere with God's plans. By using his magic to work things out the way he thought they should be, he was depending on himself and his own powers rather than the Lord. In a way, he was putting himself in the place of God by determining when and how to change things to his advantage. And that, my friend, is what is wrong with magic--even magic that is intended to be used for good. In fact, that's what's wrong with any gift of God that is misused. The ability to sing or teach or play an instrument is a gift from God, but those things can fill a person's heart with pride if they're not careful.
The moral of the story? God has given us many gifts, but we must be careful not to abuse those gifts. Without wisdom and a pure heart, even our best intentions can go astray. And, as was the case with Merlin, if the gift is one that would turn our hearts and attention away from God, it might be best to leave it be because, like Merlin, we cannot see the big picture, and we may end up causing more harm than good.