Re: Black Magic.
Well, Islam has taught us that our souls are all portions of God's soul, correct? Now there are certain practices, or rituals, you perform (involving sexual acts and/or blood usually) to establish communication with jinn. I am not sure if the ritual itself allows them to make the interdimensional "warp" to our dimension/universe or if it's the actual pact you create. But once you have communicated with a jinn, you're selling your soul to the jinn in return for their services. In doing so, you are also selling a part of God's soul and therefore permanently barring you from ever entering Jannah.
Jinn, like Shaitan (keeping in mind that Shaitan himself is a jinn), have the ability to get into people's minds and influence our thoughts at their will. Once you understand that concept, I'm sure you can imagine how they can create tensions between husband and wife, family, friends, siblings, or anyone.
*Edit - I hope Allah (swt) forgives me if I have made any errors in what I posted.
Peace Leopraecordia
This post has just as much pseudo-science in it as it has pseudo-religion. LOL ... It made me smile. What made me smile even more was that teelobhain found it scary.
It is true that all life has been created from the Ruh of Allah (SWT), (Spirit of God), however the Spirit of God is part of Creation - it does not constitute a part of God - That term is actually a misnoma - God is One and does not have parts.
This soul trading stuff - That is false. Amongst Jinn are good and bad just like with humans. There is a masjid near historic Makkah (within modern Makkah boundaries) called Masjid Jinn. It was there where Muhammad (SAW) gave dawah to Jinn and a mass conversion of Jinn took place. Amongst the people who will go to hell or heaven Jinn are counted. There may well be lots of Jinn in Jannah.
Traditional Islam teaches us that Jinn (the whispers of Shaitan) are weak. The stronger evil to contend with is our own hawa > Human desire is harder to fight than the whispers of Jinn.
Black Magic is possible usually the worst kinds are using some kind of shaitanic agent, be it a toxin or a Jinn, or both. The power of the mind itself and techniques which involve accessing the deep psyche of people via hypnosis, NLP, etc are all forms of Black Magic, but we understand these today in the domains of science. We don't need to be scared of this stuff, just be stern and it will be them (the evil ones) who are scared.