At the begining of Islam, drinking alcohol was allowed. The prohibition went through stages. Some say it was so to allow those who got used to drinking to easily give it up.

Stage One: Educating people that the harm of drinking wine is greater than its

benefits. "They ask thee concerning wine and gambling. Say: in them is great sin

and some profit for people: But the sin is greater than the profit..." (2: 219)

Stage Two: Encouraging them not to go to prayer intoxicated. "Oh you who

believe! Approach not prayers in a state of intoxication until you can understand

all that you say…” (4: 43)

Stage Three: After understanding and practising the above, the total and decisive

prohibition of wine was declared: “Oh you who believe! Truly intoxicants and

gambling and divination by arrows are an abomination, of Satan's doing: avoid it

in order that you may be successful.” (5: 90)