The Bible clearly condemns the practice of trying to communicate with those who have died. Consider the following sections of Scripture.
“Let no one be found among you who sacrifices their 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; because of these same detestable practices the LORD your God will drive out those nations before you. You must be blameless before the LORD your God. The nations you will dispossess listen to those who practice sorcery or divination. But as for you, the LORD your God has not permitted you to do so” (Deuteronomy 18:10-14).
“When someone tells you to consult mediums and spiritists, who whisper and mutter, should not a people inquire of their God? Why consult the dead on behalf of the living? Consult God’s instruction and the testimony of warning. If anyone does not speak according to this word, they have no light of dawn” (Isaiah 8:19-20).