God forbids involvement with any aspect of the occult. It's in the Bible, Deuteronomy 18:9-13, NIV. "When you enter the land the Lord your God is giving you, do not learn to imitate the detestable ways of the nations there. Let no one be found among you who sacrifices his son or daughter in the fire, who practices divination or sorcery, interprets omens, engages in witchcraft, or casts spells, or who is a medium or spiritist or who consults the dead. Anyone who does these things is detestable to the Lord."

The future is known only by God, not the dead. It's in the Bible, Isaiah 8:19, TLB. "So why are you trying to find out the future by consulting witches and mediums. Don't listen to their whisperings and mutterings. Can the living find out the future from the dead? Why not ask your God?"