The red string is meant to avoid the 'evil eye' or bad energy from other people...
Red is the colour of life en wanting to accredit, receive it. The string is always worn on your left hand ; according to Kabbalah this is the receivers side of your body. Of course, anyone can wear such a string but it only offers protection if you're not a negative 'vibe' yourself. So the string also works as a reminder to be aware of what you are doing in and with (your) life. The way to knot is also important ; 6 knots have to lie on top of each other and represent each a different prayer ....
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If religion was something I'd be in to...I guess Kabbalah or Buddhism would be the closest to me ... at this point, let's say I'm Agnostic ...
