1 Samuel 28 - G. Campbell Morgan's Exposition on the Whole Bible

It is strange how this story has been made to serve in defense of things occult, which, as a matter of fact, it condemns. Let it be carefully read, and it becomes perfectly patent that this woman had nothing to do with bringing up Samuel. Still practicing her black art, and that in secret, because of the king's edict against all of her class, she commenced, on the occasion of Saul's visit, to practice the deceptions with which she was familiar. When in response to her incantations, as it seemed, Samuel actually appeared, she was startled beyond measure.

That Samuel actually did appear to Saul there can be no doubt. However, he was sent of God for the express purpose of delivering the terrible message to Saul, to which the king listened in amazement. It was the pronouncement of his doom, and the call from the other side to the spirit of the man who had so utterly and disastrously failed to fulfil his opportunity.