Halal and Haram
The Prohibition of Things is Due to Their Impurity and Harmfulness:
It is the right of Allah, the One Who created the universe and bestowed innumerable favours upon mankind, to legalise or prohibit as He deems proper.
In Islam things are prohibited only because they are impure or harmful. If something is entirely harmful it is 'haram', and if it is entirely beneficial it is 'halal'; if the harm of it outweighs its benefit it is haram, while if its benefit outweighs its harm it is halal. This principle is explained in the Qur'an in relation to wine and gambling:
"They ask you concerning wine and gambling. Say (O Prophet); in them is great sin and some benefit for human beings, but the sin is Greater than the benefit..."(Qur'an, Al-Baqarah 2:219)
Another Islamic principal is that if something is prohibited, anything which leads to it is likewise prohibited. By this means Islam intends to block all avenues leading to what is haram. For example Islam has prohibited adultery, it has also prohibited anything which leads to it or makes it attractive such as seductive clothing, private meetings and casual meetings between men and women, the depiction of nudity, pornographic literature, obscene songs, and so on.
One of the beauties of Islam is that it has prohibited only such things as are unnecessary and dispensable, while providing alternatives which are better and which give greater ease and comfort to human beings.
Allah has prohibited seeking omens by drawing lots but has provided the alternative of istikhara, which is to ask guidance from Him in making a choice between two conflicting decisions. He has prohibited usury but has encouraged profitable trade. He has prohibited gambling but has encouraged healthy forms of competition such as sport.
He has prohibited adultery, fornication, and homosexuality but has encouraged lawful marriage.
He has prohibited intoxicating drinks And He has prohibited unclean food but provides alternative wholesome food.
"O you who believe! Do not make unlawful the good things which God has made lawful for you. But commit no excess: for God does not Love those given to excess."(Qur'an, Al-Maidah 5:90)