Answer
Salam (Peace) Dear Homer,
Thank you for your question and for contacting Ask About Islam.
“Allah” is the name of the creator, the one who created us and created this whole universe. “Allah” is an Arabic word which is a proper name that does not have a feminine or a plural; just like the name “Adam”.
For example, goddess and gods are the feminine and plural forms for the word “god” the translation of which in Arabic is Ilah; similar to English, it can have both feminine and plural forms while Allah doesn’t.
In the Arabic language, Allah is the only way to say God. It does not matter what religion an Arab follows, he or she must pray to “Allah”.
Go to Google translator and type the word “God”, the result in Arabic is the word (Allah) and everyone acknowledges Him as the creator including all Arab Christian denominations without any exception since it says so in Genesis; on the first page of the Old Testament of any Christian Gospel which says:
“At the first God made the heaven and the earth…” (http://saintscriptures.com/genesis.asp). Also please ask an Arab Christian how he says God, the creator, in Arabic.
In the English language the words “Allah” and “God” with capital G are interchangeable. Please find at the following link the Arabic version of the first page of Genesis which clearly has the word (Allah) repeated many times: http://www.usislam.org/allah/allahgod.htm
The following verse from the Quran is also telling us that our God is one and the same:
{And argue not with the People of the Scripture unless it be in a way that is better, save with such of them who do wrong; and say: We believe in that which has been revealed unto us and revealed unto you; our God and your God is One, and unto Him we surrender.} (Al-Ankaboot, Chapter 29, Verse 46)
The translation of verse 23:91 that you have quoted is:
{Never Allah has begotten a son, nor is there any god besides Him. Had it been so, each god would govern his own creation, and each would have tried to overpower the others. Exalted is Allah, above the sort of things they attribute to Him!} (Al-Muminun, Chapter 23, Verse 91)
This verse is explaining that God unlike man is not in need of sons and daughters. Procreation is an attribute of people in order to preserve the humankind while God is one and only, He is the creator and everything else is His creation including Adam and Jesus (peace be upon them).
Adam was created without a mother and a father while Jesus was created without a father; when God wills something all He has to say is be, and it is. Also the idea of many gods governing the universe is belittling the power of God.
Regarding the prophecies of Muhammad (peace be upon him), we have recently answered it and you will find it at the following link:
What Is the Proof That Muhammad Was a Prophet?
The best bounty that Allah has given Muslims is that He has guided us to His religion, Islam, which is a concept not attributed to a place or a person, meaning to submit to God’s will in order to attain peace in this world and in the hereafter.
Also Allah has provided everything for us in this world; in the following verse Allah is simply showing us His unlimited bounties and on the Day of Judgment He will judge between us, each one of us will surely be questioned about our own actions but not others.
{Say: Who gives you provision from the sky and the earth? Say: Allah, Lo! We or you assuredly are rightly guided or in error manifest. Say: Ye will not be asked of what we committed, nor shall we be asked of what ye do. Say: Our Lord will bring us all together, and then He will judge between us with truth. He is the All-knowing Judge.} (Sabaa, Chapter 34, verses 24-26)
Finally, we must acknowledge that we have different beliefs but that does not mean we cannot live in harmony in this world. Our duty is to accept our differences and expand our understanding about each other’s faith.
I hope this helps answer your question.
Salam and Please keep in touch.