Tarot cards are cardboard with images imprinted on them, then laminated. There is nothing evil about cardboard. Evil is all about intent, and the interpretation of evil has everything to do with perceptions.
Take for example, someone who gets a job at a slaughterhouse. The man working at the slaughterhouse has to kill cattle as part of his job. And in doing so, he feeds his children with his weekly paycheck. He goes to church every week with his family and is a god-fearing christian in all respects.
Now someone who is an animal rights activist looks at his job and declares that we shouldnt kill cattle. Is the man evil to that activist?
Then a person from India comes along and sees the slaughterhouse. Hindus hold cattle to be sacred animals - even McDonalds markets burgers made of venison in India. Does the Hindu think the man is evil for his job at the slaughterhouse, despite the fact that he is able to feed and clothe his children?
But you didnt ask about animals, you asked about Tarot. In actuallity, I find absolutely no link between "evil" and tarot. Certainly many people who are interested in the occult are also interested in tarot. But interest in the occult does not make a person evil. And certainly many people who are Wiccan are also interested in tarot. I have yet to meet an evil Wiccan. That still does not present a convincing link between evil and tarot.
Some people are convinced the messages in the tarot come from the devil, like the devil bothers to stand over our shoulder whispering tarot card meanings in our ears or something.
Personally I believe there are "evil" spirits, but they aren't standing around trying to tempt us into betraying our ethics. It's far too easy for us to do that on our own. Evil is evil.
And people who receive readings, well we aren't telling them how to live their lives are we? They don't HAVE to do what we say do they? Now I agree that it's unethical to represent that the tarot reader absolutely knows your future to the Nth degree. But ethics and evil are different things. If that reader didnt have tarot, they would find another way to be unethical and mislead people.
OK so maybe it's the many parts of the bible that talk about people who prophecy. Well, lots of people point to deuteronomy (mostly Moses' laws) about that, don't they?
I am fond of the following passage from Luke 10:25-28:
25 And, behold, a certain lawyer stood up, and tempted him, saying,
Master, what shall I do to inherit eternal life?
26 He said unto him, What is written in the law? how readest thou?
27 And he answering said, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy strength, and with all thy mind; and thy neighbour as thyself.
28 And he said unto him, Thou hast answered right: this do, and thou
shalt live.
With those phrases, Jesus tells us "Hey, throw out Deuteronomy, you don't need it any more."
Also, 1 John 4:16 is even better:
16 And we have known and believed the love that God hath to us. God is love; and he that dwelleth in love dwelleth in God, and God in him.
To sum: Evil is about intent. As long as you believe in God and believe that Tarot is in fact a gift from God, then tarot will never be evil. If you do believe that tarot is evil and use it while feeling slightly naughty at the time, then to you tarot is evil.