What does Sacred Scripture say? What does the Church say?
Many Catholics today seem to think that going to tarot card readers, fortune-tellers and psychics is harmless fun and another form of entertainment. The Church is very clear and explicit in her teaching, which comes from Sacred Scripture, God’s inerrant word:
Let there not be found among you anyone who immolates his son or daughter in the fire, nor a fortune-teller, soothsayer, charmer, diviner, or caster of spells, nor anyone who consults ghosts and spirits or seeks oracles from the dead. Anyone who does such things is an abomination to the Lord (Deut 18:10-11)
The Catechism of the Catholic Church is also very clear.
All forms of divination are to be rejected, recourse to Satan or demons, conjuring up the dead or other practices falsely supposed to unveil the future. Consulting horoscopes, astrology, palm reading, interpretation of omens and lots, the phenomena of clairvoyance and recourse to mediums all conceal a desire for power over time, history and in the last analysis, other human beings as well as a wish to conciliate hidden powers. They contradict the honour, respect and loving fear that we owe to God alone (CCC, 2116)
Only God can see what the future holds; neither angels nor fallen angels (including Satan) can do this. To claim to do so puts oneself on the same level as God and therefore one blasphemes and breaks the First Commandment.
Attendance at these things invites not God but the demonic into one’s life, and so the soul can be opened up to the influence of Satan. It is like knocking a door without knowing who will answer or what might happen.
Exorcists remind us that many cases of demonic infestation and oppression and even possession can be traced back to involvement in the occult.
Trust in the Lord with all your heart and lean not on your own understanding (Proverbs 3:5)