>>77815326Necromancers can't tell the future anymore because Jesus admitted all dead souls into Heaven. Before that, in the times of King Saul, it was possible for necromancers to contact souls in Limbo. Since those souls exist outside of time, they could tell you the future so long as it had been perceived by a human whose dead soul entered Limbo at some point.
Indeed, Saul not only didn't heed the necromancer's advice, but he had previously banned necromancy altogether, and seeking one's advice was hypocrisy. Perhaps his dislike/distrust of necromancy was the reason he didn't heed the advice.