If there really exists a GOD, who is 100% perfect, then such God should make a 100% perfect revelation at the very first time. 

But if a human is doing a Drama of revelation at his own, then the revelation will not be perfect, but it will have human errors in it. And this human-made revelation has to go through hit and trail method, in order to become error free.

Another sign of a human-made revelation is that it will follow the worldly wishes of the person who is making it. 

If we look into the revelations in Islam critically, then we will find out that they are absolutely not perfect, but they are based on human error, hit and trial method, and following the worldly wishes of Muhammad and the people around him. 

Let us see the case of Zihar

In Arabs of time of ignorance, if one in anger (or even by mistake) told his wife that she looked similar to his mother, or her back looked like his mother's back, then he had to separate himself from his wife as if divorce had happened. It was really a one foolish practice of the people of time of ignorance. 

Islam continued with this foolish practice of Zihar. 

Therefore, once a companion of Muhammad divorced his wife (whose name was Khuwaylah) through Zihar. She came to Muhammad and complaint against it. But Muhammad didn't solve her problem. In fact, opposite to her wish, Muhammad told her that his husband said that she was like his mother, so he was no more her husband, but now he was like a cousin brother to her (Note: In Islam, after divorce it is almost impossible for wife to remarry her husband, till she undergoes the shameful practice of Halala. Nevertheless, Zihar is even stricter than Talaq, as a pair is unable to join each other in the case of Zihar, even after Halala).

Upon that Khuwaylah (the female companion) became furious and she didn't agree with Muhammad, and she didn't go away, but she kept on disputing with Muhammad.

After sometime, in order to get rid of her, Muhammad claimed that the revelation was coming to him, where Allah gave the good news that the Zihar had been abrogated, and thus Khuwaylah could then return to her husband:

Quran 58:1-4:
Certainly has Allah heard the speech of the one who argues with you, [O Muhammad], concerning her husband and directs her complaint to Allah. And Allah hears your dialogue; indeed, Allah is Hearing and Seeing. If any men among you divorce their wives by Zihar (calling them mothers), they cannot be their mothers: None can be their mothers except those who gave them birth. And in fact, they use words (both) iniquitous and false: but truly Allah is one that blots out (sins), and forgives (again and again). Those who call their wives their mothers then revoke what they had said, should free a slave before having physical contact (with them). This is to warn you, as God is aware of what you do. If one does not have the means (of doing so) then he should fast for two months continuously before he has physical contact; but anyone who is unable to do so, should feed sixty needy persons.

Divine revelation should be 100% perfect, without any Hit & Trail Method. 

The commandment of normal Nikah and Divorce was revealed earlier, but still Allah continued the evil practice of Zihar.

Why? 

Why didn't Allah prohibit the Zihar, along with other foolish ways of divorces (like Ila) earlier on his own? If Allah is 100% perfect, then he would have prohibited it earlier on his own.

While Allah neglected his duty of prohibiting it on his own, therefore later this poor woman had to have a continued dispute with Muhammad for its abrogation. 

And Prophet Muhammad is also strange. Even the women knew it that Zihar was just evil and foolish, but Muhammad didn't show this awareness, and he didn't ask Allah for its prohibition, but he kept on telling the woman to forget her husband and to go away.

And if 100% perfect Allah had not prohibited the Zihar earlier, then He could have abrogated it immediately when the poor woman asked for it for the first time. But no, again Allah had to first watch the whole Drama of dispute between the woman and Muhammad, and when even after that woman didn't agree to leave him, only then the revelations came, so that Muhammad could get rid of her. 

But in these verses too, the so-claimed 100% perfect Allah showed that he is Not Wise enough to handle this problem properly. 

But first please read how Khuwayla paid the penalty at her own secretly, and his husband even didn't know it:

Sunan Abu Dawud 2214:

Narrated Khuwaylah, daughter of Malik ibn Tha'labah:
My husband, Aws ibn as-Samit, pronounced the words: You are like my mother. So I came to the Apostle of Allah (peace_be_upon_him), complaining to him about my husband.
The Apostle of Allah (peace_be_upon_him) disputed with me and said: Remain dutiful to Allah; he is your cousin.
I continued (complaining) until the Qur'anic verse came down: "Allah hath heard the words of her who disputeth with thee concerning her husband…." till the prescription of expiation.
He then said: He should set free a slave. She said: He cannot afford it. He said: He should fast for two consecutive months. She said: Apostle of Allah, he is an old man; he cannot keep fasts. He said: He should feed sixty poor people. She said: He has nothing which he may give in alms. At that moment an araq (i.e. date-basket holding fifteen or sixteen sa's) was brought to him.
I said: I shall help him with another date-basked ('araq). He said: You have done well. Go and feed sixty poor people, and return to your cousin.
(Abu Dawud said) She paid the penalty secretly, without telling her husband
(This tradition is "Sahih" i.e. authentic. Link)

Please note:

  • The woman paid the penalty at her own. 
  • Is it not strange and foolish that mistake of Zihar was made by the husband, but the penalty was given by the poor woman? What type of Divine Justice is this? 
  • And why did Allah not make it totally a non-issue by totally abrogating it? We see in the non-Muslim world that there is absolutely no issue of Zihar here. So why then did Allah keep on sticking to it in one way or another in the name of penalties? Especially the one who is paying the penalty, it is only the woman. 

Only husband has the right to Zihar, while woman has no right

You could see more double standards here. 

When a woman says that his husband is like her father, then there is no problem even if she utters these words millions of times, and her husband could continue having sex with her (see the detailed fatwa here). 

If uttering the words of Zihar really have some effects, then it should have brought the equal effects for both man and the woman. But it didn't. One can only wonder what type of Divine Justice is this that only man's words have the effect. 

Reality is this neither man's nor woman's words have any effects. It is totally a non-Issue and foolishness and ignorance of old culture. But 100% perfect Allah was not able to get rid of it. It is due to the reason Muhammad was not in contact with any such Allah in the heavens, and he was making all these revelations at his own, therefore we are seeing these human errors in the revelation. 

Zihar vs marrying the wife of Adopted son

On one side it is a logic of Islam if man says someone his son millions of times after adapting him, still that child/person cannot become Mahram to his family. Thus, a foster mother should be separated from her adopted son as soon as he becomes an adult, and the son should be kicked out of the house as he could no longer stay under one roof with his foster mother. 

On the other side it is also a logic of Islam that saying a wife that she looks like his mother, is going to divorce her permanently. 

These are only the double standards of Islam.

PS:

Both, Shia and Salafi(/Wahabi) Muslims accept Zihar, although they deny 3 Talaqs in one sitting, and take pride in it while condemning traditional Sunnis for accepting 3 Talaqs in one sitting.

But we want to tell these Shia and Salafi Muslims that their Quranic Zihar also happens in one sitting, just like 3 Talaqs in one sitting. 

Therefore, your religion is illogical, and taking pride in it is foolish too.