And many branches of Christianity (especially Catholics and Orthodox) know and use the power of images. I teach medieval and renaissance art and I deal with images of the divine, with symbols and the relationship between viewer and image all the time.
Illuminated hand written books - church frescoes - paintings of Last Supper or Annunciation - sculptures of saints - they are more than pieces of parchment, pigments, oil, wood or marble because of the meaning the viewer invests in them and the skill of the artist who makes this meaning visible. It's communication by visual means - a visual language, and only with secularism after the renaissance modern art developed. Modern in the sense of - art no longer as tool for conveying church-approved messages but as tool for personal expression, social criticism, aesthetic experiment or whatever.
Tarot cards for me are a branch of communicating art. Each artist interprets the tarot archetypes and scenes in a different way, but they are still recognisable. If you put the Star from many different decks next to each other, they will look very differently and convey different aspects of the card, but you will be able to recognize a core meaning. (If it's a real tarot deck and not an oracle.)
The images of the tarot, especially the major arcana, reflect values of Christian, Western society. The image of temperance or justice were as well known until recently as today logos of Adidas and Nike. If you look at Cesare Ripa's Iconographia or other collections of symbols and emblems, you will recognize the tarot archetypes.
The church probably didn't like losing their monopoly of interpreting these images. But that doesn't change the fact that modern tarot cards have strong roots in Western culture.
And as such, I'm not a bit afraid of them. I feel my own roots in this culture, the bad and the good, very strongly, and I can connect to them on many levels. Emotional, artistic, historical, psychological, divinatory, autobiographical....
I'm afraid of many things, but not of tarot cards. I feel that many prejudices against the cards are based on ignorance or superstition which I cannot remove or fight against.
The human heart and mind are dangerous. Tarot, that helps us clear up our aggression, fear, shame and pride, is a good thing, just like meditation, an open conversation, a good therapy session, a walk by the sea side... and it has the added advantage of precision and clarity, the better you get to know the images.
Can you use tarot to manipulate others? Yes of course. But you can also use love to manipulate others.