Well I believe, for many reasons.
Also I purchased a pack of angel cards for myself and one for my daughter and I used them fairly often. I think there are 44 cards - if that is relevant.
On using them say ten times, on eight occasions a particular card came out. It was 'Serephina'. I happened to mention this to my daughter who confirmed that she has had this card a few times also.
Neither of us could actually see how it was relevant to us as it told of a 'happy change or addition to the family'. I just kept worrying that my daughter would end up pregnant. As it turned out, another further removed family member announced that she was pregnant within two weeks.
I still use my cards when I feel troubled, they have been very well shuffled and cut and shuffled and there are many cards that have not come out for me, I often get the same messages and they are usually relevant.
I accept that the messages are vague and obviously designed to be uplifting but hand on heart, just skipping through them now, they are many that would not be relevant (unless my circumstances were to change).
I sent a pack to a dear friend who lives in another country and we were Skyping one evening and decided we would use our cards. We both chose one card out of the pack - and we both got the same card. I dont know what the odds of that are but I was fairly surprised by it.
Last December I did a spread of cards. Three times. Each time a particular card came out which was something that really pleased me but I was feeling sceptical. I put all the cards together shuffled and shuffled and cut and then asked my guardian angel, 'If this is true and this is what you want me to know, then this card will come out next' and it did. Absolute confirmation.
I dont make major decisions based on the cards but I do find them very comforting sometimes.