Every child is born knowing that his or her Lord is Only One, Allah, regardless of what faith his or her parents may practice. But just because a child is born with this fitra, or natural belief, does not necessarily mean that the child will grow up to be what truly makes a person Muslim, which is ones iman. A Muslim must have belief and iman in the following:
Our Iman is not always as sound and strong as we want it to be as it often fluctuates according to life circumstances. There are several causes for weakening Iman such as deficiencies in our prayers or the insinuating whispers from the Shaytan. Regardless of the cause, it is crucial for all of us to keep a check on our Iman and if we feel it is faltering in any way then we should take measures to restore it. It is our responsibility to know which things decrease our Iman and how to avoid them and those that increase our Iman and how to embrace them.
Allah is the proper name applied to the true God who exists necessarily by Himself comprising all the excellent Divine names and attributes of perfection. Allah is One and Unique. He has no son, no partner, nor equal. He is the sole Creator and Sustainer of the universe. Every creature bears witness to His Oneness, Divinity, andRububiyyah [inf. of Rabb], and to the uniqueness of His Attributes and Names.
The importance of this topic is directly related to the importance of Tawheed (Islamic monotheism) and the perfection of Tawheed in one's life and actions. As a scholar of old said that whoever does not know where His Creator is does not worship Him.