You seem to be confused my friend. We study real magic which is akin to prayer, what you are thinking is a work of fiction and not done in reality. I know how silly i must sound saying this magic is real while that magic is not, but if you actually studied and understood magic, you would realize magic used by spells is energy which only effects energy. It is also subtle and not seen by the human eye, you also can't say some words and have lightning shoot from your wand. If you wish to defend yourself for whatever reason, you could cast a protection, or possibly a curse, but don't expect a dramatic show of force.