The Oneness and Unity of God is the first and the most important belief in Islam. It is the first part of the declaration of faith (Shahada), which people must recite to become Muslim. The Oneness and Unity of Allah (s.w.t) means that, there is no God but Allah (s.w.t), there is nothing like Allah (s.w.t), and that Allah (s.w.t) is not made up of parts. The belief that there is no God but Allah (s.w.t) and that there is nothing like Him is easy to understand. However, the belief that he is indivisible, and not made up of parts needs some explanation.
For example, if we were to look at a motorcar, we find that it is made up from different parts, and only when those parts come together, can we call it a car. So a wheel on its own is not a car, and the same goes for the doors and the mirrors. So we can understand that a car needs an engine, wheels, doors and other parts for it to be a car and for it to work.
However, when we think of God we understand that He is not in need of anything to complete Him, that He is not made up of parts. Understanding the Oneness of God is an important first step towards understanding God’s attributes such as knowledge, power and others. Therefore, the attributes of God, such as the power and knowledge of God, are not separate from his essence, but are part of his nature and are intrinsic qualities.