In my younger years, I once dabbled in fortune telling. I read books on astrology and knew how to plot and interpret the planets on a chart. I had a deck of tarot cards and practiced it. The more I practiced them, the more accurate these become. I am telling you that these things do work. That is right, these things do work and they are real. But are these practices pleasing to the Lord?
As I began to read the scripture, I learned that I become detestable to the Lord because I practice these arts.
"Let no one be found among you 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... 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." (Deut 18:10-14)
God calls everyone to be holy. This is the vocation of every living human being. Holiness is achieved only by listening to and obeying the Lord. If we practice or listen to divination we are not listening to the Lord but we are listening to something else. If "Rebellion is like the sin of divination." (1 Sam 15:23) it follows that divination is like the sin of rebellion. And rebellion is the sin that condemned for eternity the most beautiful angel God ever made.
When I point this out to Christians talking about horoscopes or zodiac signs, the answer I often get is that they are doing it for fun - it is a game. If that argument is valid then I can say that it is alright to play with a bomb. Consulting the horoscopes or delving in astrology and fortune telling is telling God that "You are just one of the forces that control my life." Undoubtedly, the planets control things on earth. The moon controls the tides of the sea. The eruptions in the sun has an effect on radio transmission on earth.
But in fortune telling, we are trusting in forces other than God. We are saying that these forces control our lives. We discount the simple fact that God is the ultimate force that controls our lives. So we turn to other gods - horoscopes, cards, ouija boards, consulting spirits, etc. And that is why we become detestable to God. A Christian who practices these arts is a contradiction to his faith. How can one say that God is Almighty if movements in his life are controlled by these arts?
What should you do if you have ever played these games? The only thing to do is to admit that you have gravely offended God. The next thing to do is to get rid of these toys. If you have cards used for fortune telling, posters, books, coffee mugs, etc - burn them - destroy them totally so that others will not fall to sin because of them. Then turn to your Father in heaven and be reconciled with him. No sin is too big for him to forgive - such is our God - our Father in heaven.