An atheist is saying: If Allah were a thing, then He would be created or there would be two of Him!
Question

                Is Allah a thing (shay’), based on the verse (interpretation of the meaning): “And of everything We have created pairs” [adh-Dhaariyaat 51:49]?
Praise be to Allah.Everything that exists may be described as a “thing” (shay’); that is, it is something that exists out there in the world.
Allah, may He be exalted, has a true Essence that does exist, so He may be referred to as shay’ (a thing), as in the verse in which He, may He be exalted, says (interpretation of the meaning):
“Say, ‘What thing is greatest in testimony?’ Say, ‘Allah is witness between me and you’”
[al-An‘aam 6:19].
So the word shay’ may refer both to the Eternal (al-Qadeem, meaning Allah) and to the created being, to the necessary being (that which must exist, namely Allah) and the contingent being (that which may exist).
In fact, concepts may also be referred to as “things” (ashyaa’, plural of shay’), because they exist in the mind, and that which does not exist may be referred to as a thing in the knowledge of Allah, although it is not a thing in existence.
Imam al-Bukhaari (may Allah have mercy on him) said in his Saheeh (9/124):
Chapter on the verse “Say, ‘What thing is greatest in testimony?’ Say, ‘Allah…’” [al-An‘aam 6:19]; Allah, may He be exalted, referred to Himself as a “thing” (shay’), and the Prophet (blessings and peace of Allah be upon him) called the Qur’an a “thing”, and it [the Qur’an] is one of the attributes of Allah. And Allah says (interpretation of the meaning): “Everything will be destroyed except His Face” [al-Qasas 28:88]. End quote.
Shaykh ‘Abdullah al-Ghunaymaan (may Allah preserve him) said:
What al-Bukhaari meant here is that Allah, may He be exalted, may be referred to as shay’ (a thing), and the same applies to His attributes, but that does not mean that ash-shay’ (“the thing”) is one of His beautiful names. Rather He, may He be exalted, may be referred to as a “thing”, and by the same token His attributes may be referred to as “things”, because everything that exists may acceptably be referred to as a “thing”.
End quote from Sharh Kitaab at-Tawheed min Saheeh al-Bukhaari (1/343).
Based on that, “ash-shay’ (the thing)” is not one of the names of Allah, may He be exalted, but He may be spoken of in such terms, because speaking of and describing something is broader in scope than names and attributes. So when speaking of Him, we may say shay’ (thing), mawjood (being, that which exists), qadeem (eternal, existing from eternity) and so on, but these are not names of Allah, may He be exalted.
With regard to the verse (interpretation of the meaning), “And of everything We have created pairs, that you may remember” [adh-Dhaariyaat 51:49]:
What it means is that Allah, may He be exalted, created things in pairs of opposites: male and female, hot and cold, night and day, and so on.
Ibn al-Jawzi (may Allah have mercy on him) said:  The words of Allah, may He be exalted, “And of everything We have created pairs” refer to pairs or opposites, such as male and female, land and sea, night and day, sweet and bitter, light and darkness, and so on. “that you may remember” means: so that you may realize that the Creator of these pairs is one.
End quote from Zaad al-Maseer (4/172).
This verse is speaking of created things, and stating that Allah made them in pairs of opposites.
Other examples include the verses in which Allah, may He be exalted, says (interpretation of the meaning):
“And that He (Allah) creates the pairs, male and female”
[an-Najm 53:45]
“And made him in two sexes, male and female”
[al-Qiyaamah 75:39].
And He says regarding Nooh (peace be upon him):
“We said: Embark therein, of each kind two (male and female)”
[Hood 11:40].
What does this have to do with the fact that Allah, may He be exalted, may be referred to as shay’ (a thing)? We are quoting these verses because an atheist said that so long as Allah is a “thing”, then there must be two of Him!
This misguided and ignorant person should be told: rather Allah was speaking of the existence of pairs of created things. Does it make sense to you – if you have any sense or reason – that the Creator, may He be glorified and exalted, would tell us in this verse that He created two other creators besides Him, because He says that He created everything in pairs?
Is this how you reason and understand?!
The verse, clearly and briefly, is speaking of the might of Allah, may He be glorified and exalted, and how He controls the universe, and that one of the manifestations of His might, power and oneness is that He has created everything in pairs.
Ibn Katheer (may Allah have mercy on him) said: “And of everything We have created pairs” means: all created things are in pairs: heaven and earth, night and day, sun and moon, land and sea, light and darkness, faith and disbelief, death and life, doom and bliss, Paradise and Hell. Even animals, jinn and humans, are male and female, and something similar may be said with regard to plants.
Hence Allah says: “that you may remember”, that is: so that you will know that the Creator is one, with no partner or associate.
End quote from Tafseer Ibn Katheer (7/424).
The Creator can only be one. It is not possible for there to be two creators then for there to be stability in the universe, because one of them would dominate the other, and thus become the only lord, as Allah, may He be exalted, says (interpretation of the meaning):
“Allah has not taken any son, nor has there ever been with Him any deity. [If there had been], then each deity would have taken what it created, and some of them would have sought to overcome others. Exalted is Allah above what they describe [concerning Him]”
[al-Mu’minoon 23:91].
Ibn Katheer (may Allah have mercy on him) said in his Tafseer:
That is, if we assume that there were a number of gods, each of them would keep control of what he had created, so there would be no order in the universe. But what we see is that the universe is in perfect order and harmony; both the upper and lower realms are connected to one another in the most perfect manner. “You do not see in the creation of the Most Merciful any inconsistency” [al-Mulk 67:3].
Moreover, each of them would seek to suppress the others and oppose them, and thus some of them would overcome others. End quote.
Perhaps another ignorant person might say: If Allah is a thing, then He is included in his words (interpretation of the meaning): “Allah is the Creator of all things, and He is, over all things, Disposer of affairs” [az-Zumar 39:62].
We say in response: Allah is the Creator of every created thing; as for Allah, He is the Creator, and the Creator cannot be created, for if He were created and made, and controlled, then the one who created and made Him would be the Creator instead of Him, and that one would be “God”!
If we assume that this second one were himself created, then he would not be a Creator either – and so on and so forth, until the matter – according to common sense, proper reasoning and logic – would lead to one Creator who is the necessary being, the thing-in-itself, who is not preceded by nonexistence and will never cease to be. He alone is the Creator, and everything besides Him is created by Him and controlled by His might. Such is the only Creator. This is what is known by people of faith, that he is “God”, the One, the Only, the Eternal.
Similarly, if someone were to say that Allah exists and everything that exists was created by Allah,
we say: everything that exists is created; Allah created it and it is impossible that the Creator could be created, as mentioned above.
To sum up, the words “thing” (shay’) and “being” (mawjood) are common descriptions that may refer to the Eternal (Allah) and that which is brought into being, to the Creator and that which is created.
When these words are used in general terms, no wise person would understand them as meaning that the Creator created Himself on the grounds that He is a “thing” and a “being” (something that exists) because it is impossible that the Creator would create Himself; that would be combining two contradictory things, combining a Creator who never did not exist and a created thing that once did not exist.
For more information, please see the answer to question no. 87677.
And Allah knows best.