Al Qadr (Destiny)

Believing in Al-Qadr (Destiny) is part of the fundamental Islamic faith.
Allah (God) is the Sole Creator and Sustainer of everything in this Universe. He has absolute Knowledge and control of everything and nothing happens in this universe without His Knowledge and Will.

Allah (God) has fixed everyones destiny.

He to Whom belongs the dominion of the heavens and the earth, and Who has begotten no son (children or offspring) and for Whom their is no partner in the dominion. He has created everything, and has measured it exactly according to its due measurements. Surah (Chapter) Al-Furqan (The Criterion) The Qur-an 25:2

Allah (God) has made right and wrong and has repeatedly told us through His Rusul (Messengers) about the difference between the two.
Allah (God) has also given us the faculty of logic to distinguish between right or wrong or good and evil. Deviating from the right path demonstrated to us by His Rusul (Messengers) is disliked by Allah (God). Our model is the Qur-an and the Sunnah (Traditions of Muhammad S); instead of doing whatever we want for the logic that since Allah (God) has already fixed al-Qadr (Destiny) for us, so there is no use of putting in the effort.

Muslims believe in the Ultimate and Absolute Powers of Allah (God) that He can do anything that He Wills.

Also, Allah (God) listens to Du'a (Supplication) of people.