***he Bible teaches that any powers you have that other people (muggles) don't have either comes from God, for His purposes only, or from Satan and the demons, even if you say you're using the power for "good".***
Excellent point.
And the good characters in HP DO use their powers for good. Protecting muggles from the bad guys, protecting other wizards from the bad guys, dieing to stop the bad guys. How is protecting the weak from the evil NOT God's purposes?!