There are over seven billion people on the face of this earth, and over a billion of them are Muslims. Six billion of the population refers to god as being in the form of an idol, such as the Buddhists, Christians, Jews, Hindus, ect.  By referring to Allah (SWT) as "god", we are bringing Allah equal to the level of the stones, wood ect. 

Satan gives us an idea, that it is not possible to explain a non-Muslim about Islam without using the term "god". It is as though Allah (SWT)'s identity has become "god".  

For example, When we talk to Buddhists, Hindus, why don't we refer to our "Buddha" or "Ram", but when we speak to English speaking people, we use the word "God".

Why did not our beloved Prophet when speaking to the people of Makkah refer to Allah as one of the gods the Makkans worshipped such as "Al-Lat" or "Huba", in order to explain the people of Makkah his message?

When we are talking to non-Muslims or non-practicing Muslims, or to simply show off, to call god to Allah (SWT), we are closing the door for non-believers about the understanding of Allah (SWT). The reason behind this is that the non-believer will think that, this man has is own god (statue) which he is trying to impose on me, in order to follow his statue. The reason being is that the concept non-Muslims have of their creator is that he has to be represented in the form of a statue. 

Another example is that if someone's name is Muhammed, and you were to refer to him as Jason. It is not possible for you to call someone by the name of Muhammed as Jason, because you have no right to change a person's original identity. Now one can imagine Allah (SWT), who is the provider and sustainer, who keeps everything in a perfect balance, what punishment will be given by him to those who refer to him as god, and to bring his status equal to the status of idols. 

What is the difference between Muslims and non-Muslims, when Allah is called "God", and by doing this we are closing the door to understand Allah (SWT). If one is using "Allah", the non-Muslim will then become more interested and curious to know who Allah actually is, and that non-Muslim can then go to the nearest library, or on the internet in order to learn who Allah (SWT) is. 

Allâh! Lâ ilâha illa Huwa (none has the right to be worshipped but He), the Ever Living, the One Who sustains and protects all that exists. Neither slumber, nor sleep overtake Him. To Him belongs whatever is in the heavens and whatever is on earth. Who is he that can intercede with Him except with His Permission? He knows what happens to them (His creatures) in this world, and what will happen to them in the Hereafter . And they will never compass anything of His Knowledge except that which He wills. His Kursî^[] extends over the heavens and the earth, and He feels no fatigue in guarding and preserving them. And He is the Most High, the Most Great. [This Verse 2:255 is called Ayat-ul-Kursî.] (2:255)

As Allah (SWT) is telling us above, that he is one who no one else is worthy to be worshipped except him, WHY? 

Because Allah (SWT) is always alive, and he is the giver of life to the entire world. And he is the one who controls the entire universe and this world. 

We should always realize that Allah (SWT) is not like his creations, who feels tired, sleepy, sick and there things go out of control. Allah is the only power who is never tired, or he is never sleepy. Whatever is in the heavens and in this world, belongs to Allah only. And no one has any authority to intercede for anyone else without his permission. 

We can see what control Allah (SWT) has that no human being can reach to Allah against his will, and he is the all knower of the unseen, and he is the knower of everything, such as the current issues. And no one can get any knowledge until Allah does not want to grant it to him. 

All the heavens and the earth is under Allah (SWT) throne. In order to take care of every small details with accuracy in order to run this universe is no big deal for Allah (SWT). 

And Allah (SWT) is the highest and no one is comparable unto Him. Who is the power what He wills happens. 

Now one should understand and realize Allah's powers by reading Ayat-ul-Kursi in his or her own language again and again and realize what crime is being committed when Allah is referred to as "God".