Definitions
Tarot means "tablets of destiny." Cartomancy is the telling of fortunes using playing cards. A popular form of cartomancy uses Tarot cards to (as it is promoted) reveal and gain insight into a person's past, present and future. Those who promote this "craft" include professional cartomancers, psychics, or those simply interested in the paranormal (New Age).
Tarot cards, created in 15th century Italy, were initially used for games of amusement. It wasn't until around the 1780s A.D., however, according to noted Tarot historian Michael Dummett, that they were first utilized for fortune telling.
The Deck
The deck used for fortune telling commonly contains 78 cards, 56 of which are called the minor arcana, while the remaining 22 are referred to as major arcana. All of them have pictures representing various forces of nature along with either vices or virtues. Major arcana have pictures symbolizing a fool, a magician, lovers, strength, a wheel of fortune, death, the devil, judgment and so on.
"The early Tarot symbolism was deeply rooted in Medieval and Renaissance Europe, but over the centuries it has grown to incorporate everything from astrology and Kabbalah to runes and the I Ching" (Encyclopedia of World Religions, Cults and the Occult).
The Reading
A question is asked and then cards from a shuffled Tarot deck are selected and arranged in a certain order. They are then interpreted to arrive at an answer. The meanings and conclusions drawn can vary greatly depending on the person offering the interpretations.
The Temptation
Our understanding on most subjects is flawed and incomplete in a variety of ways. A good chunk of our life, therefore, is spent seeking the help of others, who we view as more knowledgeable than ourselves, with our problems. We are born needing the assistance and guidance of a whole host of individuals in order to live in this world.
Fortune telling Tarot cards, Ouija boards, astrology, horoscopes and alike all appeal to our need to gain understanding and assurance from something greater than we are. The problem is these methods are based entirely on circumventing God in favor of sources that are not looking out for our best interests (to put it mildly).
Power Source
Ultimately, spiritual insight and the manifesting of power are derived from only two sources. The first is the true God of the universe (or his righteous angels under his direction). The second is Satan the devil and his demons.
A person who claims neither access to God or demons, but states they can tap into "other worldly" spirits or generic powers is a liar. They are relying on the imaginations of their own heart, which has been deceived by the "god of this world" (2Corinthians 4:3 - 4) to trick and steal from other deceived people.
Warnings
Biblical verses such as Deuteronomy 18:9 - 14, Leviticus 19:26, 31, 20:6, 27, Isaiah 8:19 - 20 and others offer stern warnings to humanity. God strictly forbids us from pursuing any supernatural insight, ability or power that does not directly involve Him. Those who rejected these warnings, in the Old Testament, and practiced the "black arts" were put to death (Leviticus 20:27). Practices such as fortune telling (using Tarot cards), witchcraft, divination, psychic readings, astrology and so on should not be indulged in.
The Solution
Tarot cards, of themselves, are not necessarily evil when used to play games of amusement such as the German Grosstarok, French Tarot or Austrian Königrufen. It is their use to deceive people and seek spiritual insight apart from our Creator that is wrong.
Only God, through the Bible, can offer true answers to our questions. He alone can provide the proper spiritual understanding and wisdom we need in our daily lives.
The fear of the Lord is the beginning of knowledge, but fools despise wisdom and instruction . . . For the Lord gives wisdom; out of His mouth comes knowledge and understanding (Proverbs 1:7, 2:6, HBFV).