I mentioned caffine right? that is also apart of a mind altering drug as well.....as I mentioned I try to avoid things with caffine.

oakie dokie

It doesn't matter who started to make it illegal, the observations of the effects can tell you why its illegal.

here some noted effects, problems of using:

• Lung problems (eg chronic bronchitis, lung cancer). Cannabis smoke contains ingredients that can damage the lungs, affect your physical health and fitness and possibly cause cancer. If cannabis is smoked over many years it may get in the way of the functioning of the lungs, this may increase the chances of developing lung disease.

• Difficulties with memory and attention - It has been shown that cannabis use over the longer term can cause problems with memory, attention and processing of complex information. This may affect everyday life when you are learning something new or doing something difficult.

• Development of dependence - most people who use cannabis don't go on to use it regularly, or develop problems with it. However, there are a number of people who will become dependent on cannabis. The chance of becoming dependent on cannabis is similar to the chance of becoming dependent on alcohol. If someone is dependent on cannabis they may experience a difficulty controlling their use or be spending a lot of time involved in cannabis and less time on other things in their life.

• Increased risk of mental health problems - some people have a greater risk of developing mental health problems than others. Cannabis use may trigger problems if you have a family history of serious mental illness (such as schizophrenia or depression), or you are vulnerable to developing it. If you already have a serious mental illness, cannabis use may make some of your symptoms worse.

Cannabis and experimentation
It is not uncommon to experiment with cannabis. Experimentation does not necessarily lead to problem use. If you are concerned about someone's cannabis use it may be helpful to speak with The Alcohol and Drug Information Service (ADIS). ADIS specialise in drug and alcohol issues. It may also be helpful to calmly talk with the person you are concerned about. Engaging them in a confrontational way may only alienate them.

Mixing cannabis with other drugs
Mixing cannabis and other drugs may be dangerous. If cannabis is taken with other drugs the effects of the cannabis may be stronger.

Cannabis and driving or operating heavy machinery
If you have been using cannabis driving or operating heavy machinery is dangerous. If you are stoned your attentions span may be less or you may find it harder to react if something unexpected happens. It is possible to experience these effects even if you don't feel stoned.

Now mankind don't you think this is a good enough reason not to use marijuana ??

Why do you want the qur'an to states so ??

You are just trying to justify your use despite the known effects, do you really need God to spell it out ??