What is belief in destiny in islam? What does belief in destiny means?
God Almighty knows all that is done by His subjects and everything that is related to all other creatures whether it already took place or will take place in the future. Everything takes place when the appointed time comes, just as Allah knew beforehand. Contrary to some people’s misgivings, there is not coercion here. This is because Allah Almighty has to know by, implication of His Divinity, what His subjects will do in the future and what will happen in His dominion. Otherwise, there would be a deficiency in Him.
Having free will, human beings are free and are not coerced. As Allah knows the past and future due to His endless knowledge, He has written what will take place. Knowing is not doing. The exact hour and minutes of solar eclipse can be computed in advance, without it following that the sun’s eclipse is being caused by the scientists’ foreknowledge. The solar eclipse is bound to happen, however scientists know this in advance through research and calculation. Knowing that something will happen and writing this and creating it when its time comes is different from willing to do that thing and act accordingly. Man wants to do something by his own free will; by implication of all his acts being a test, Allah has left him free. He only creates the act that man wants to perform. However, while Allah is content with good and right actions, he is not content with evil actions.
 For details in the matter of creed see http://www.islamicpublishings.net/images/book/ingilizce/islamimanibadet_ing.pdf
Source: Dr. Murat Kaya,The Final Divine Religion: ISLAM