The incident where Saul, in dire straits, calls on the woman with the familiar (evil) spirit to seek his fortune has been a source of controversy for many for years. I think John Gill gives the most plausible explanation. He believes the apparition she calls up is an evil spirit. The apparition (not Samuel who was in heaven) says, “Moreover, the Lord will also deliver Israel with thee into the hands of the Philistines,”….no comfort, “it being the business of this foul spirit to drive him to despair by the permission of God.” Had it really been Samuel he would have called him to repent, especially regarding David, and advised him to send for him, who might have been of singular use unto him; had Saul complied God would have appeared for him, and worked deliverance, “and tomorrow [shalt] thou and thy sons be with me.” This was a lie of the devil; if he meant this of himself, as an evil spirit, it could not be true of Saul and all his sons, that they should be with him in hell, especially of Jonathan who appears throughout the whole of his life to have been a godly man; if he would have it understood of him as representing Samuel, and of their being with him in heaven, it must be a great stretch of charity to believe it true of Saul, so wicked a man, and who died in the act of suicide; if the spirit meant all the sons of Saul, as the expression seems to suggest, it was mistaken as Ishbosheth, and his two sons by Rizpah, survived. It is noteworthy that this sin is recorded as the one specifically among many for which Saul died (I Chron.10:13).