Leviticus 20:5-6

5then I shall set My face against that man and against his [extended] family, and I will cut off from their people both him and all who follow him in playing the prostitute (commit apostasy) with Molech.

6‘As for the person who turns to mediums [who consult the dead] or to spiritists, to play the prostitute after them, I shall set My face against that person and will cut him off from his people [excluding him from the atonement made for them].