The idea that casting spells is an important part of Wicca is a common misunderstanding. The fact of the matter is that spells have no part in the religion of Wicca. A Wiccan could cast spells if they wished, but they certainly don't have to do it. In fact I, and many other Wiccans, rarely if ever cast spells.
That being said, magic is a core part of Wicca and sometimes the misunderstanding is the difference between using magic and casting spells. Magic is a core belief of Wicca. We use magic to cast a circle, consecrate our tools, Draw Down the Moon, etc. None of these things involve spells, but they certainly require magic.