"...do not inquire after their gods, saying, 'How did these nations serve their gods? I also will do likewise.' You shall not worship the LORD your God in that way; for every abomination to the LORD which He hates they have done to their gods" (Deuteronomy 30:)
Many of man's religious holidays are repackaged versions of the very pagan festivals that God hates and forbids His people from following. Are you worshiping God the way He wants to be worshiped?