Does one who denies the existence of magic commit an act of disbelief?

Denying the existence of magic entirely is a denial of the verses that mentioned magic, and it is an act of disbelief (kufr) and apostasy from the faith. As for denying the reality of magic and claiming that it is mere illusions, this contradicts the apparent meanings of the texts, but it is not a disbelieving statement, as Islamic scholars have differed on this issue, and some of them have held that it is deception and illusion. This matter is among the jurisprudential branches and not among the fundamentals of religion.