Some non-Muslims especially the Christians criticize and speak against Islam saying that Islam allows men to beat their wives. They refer to Quran 4:34 and pour out their inner filth.

Lets have careful look into the issue;
Firstly, you cant just take a word of the Quran and comment the way you like. You ought to consider the whole Islamic moral and social make up, make a study in the very same context and then form your opinion;

Now consider the following points;

The context:

1-Islam asks both male and female to restrict themselves only to their spouses.
2-Islam, in the strongest manner possible, condemns every extra-marital relation.
3-The permission to (lightly) beat women is not unconditional, nor it is in every situation. Lets see the context of the that; Quran says:

"....therefore the righteous women are devotedly obedient, and guard in (the husband's) absence What ALLAH would have them guard. As to those women on whose part ye fear disloyalty and ill-conduct, Admonish them (first), Next, refuse to share their beds, (And last) beat them (lightly); But if they turn to obedience, Seek not against them, means (of annoyance): For ALLAH is Most High, Great (above you all)." (Quran 4:34)

This makes it absolutely clear that this permission is only when women become disloyal--And again reading from start makes it clear that disloyalty here means something below dignity of a modest and chaste woman.

4-When a woman indulges into such an act then of a surety she would not be to her husband as she ought to be. This can even possibly make her husband slip away form the right path and he may get involved somewhere else. If such a stage arrives then this would be havoc not only for the couple and their relations but for the society as a whole. And this permission is deterrence and a necessity against evil.

It's allowed in extreme cases only:

1-Even in that case, to beat is the last option. First is to admonish, if this does not work then next step is to part from their beds, and if this also fails then is light beating.

2-And even if such a stage arrives then also their are restraints, "But if they turn to obedience, Seek not against them, Means of annoyance"

3-If at all a woman feels that she cannot live with her husband anymore, for any reason, she must get divorce and part, but as long as she is inside the marriage she must remain loyal to her husband even in his absence. For the mutual relation of the couple is the very basis of the society.

An Important Instruction:

When interpreting a verse we have to take in consideration the Hadith of Holy Prophet (peace be upon him). He said;

"Fear Allah concerning women! Verily you have taken them on the security of Allah, and intercourse with them has been made lawful unto you by words of Allah. You too have right over them, and that they should not allow anyone to sit on your bed whom you do not like. But if they do that, (in that case) chastise them in a way that leaves no mark (i.e. not severe). Their rights upon you are that you should provide them with food and clothing in a fitting manner."
(Sahih Muslim, Hadith 2137)

This shows it is more of a psychological thing then a physical one and the purpose is only to maintain the chastity and mutual love and affection of the spouses. If a wrong conduct of the woman is not checked then surely the relation will be adversely effected.

Why there is no legislation for wife doing the same to her husband:

Remember man can have legitimate second wife but woman can't have two legitimate husbands at a time for obvious reasons. Considering this and the more obvious psychological, physical differences and considering real life facts there is no legislation regarding wife admonishing her husband this way. She may take up the issue with the elders of both families to correct her husband.

An unauthentic narration:

Some people try to mislead by quoting a narration which goes as:

Narrated Umar ibn al-Khattab: The Prophet (pbuh) said: A man will not be asked as to why he beat his wife. (Sunan Abu Dawud Hadith 2147. Albani classified it as Da’if i.e. unauthentic).

Besides Albani, Ahmad Shakir and Shu’aib ‘Arna’ut also graded it Da’if in their respective classification of Musnad Ahmad. Ibn Kathir also criticized its chain in Musnad Al-Farooq 1/182.

The Holy Bible:

Having known the Islamic view point now lets compare it with what Bible has to say about it;
Bible says;

"When men strive together one with another, and the wife of the one draweth near for to deliver her husband out of the hand of him that smiteth him, and putteth forth her hand, and taketh him by the secrets: Then thou shalt cut off her hand, thine eye shall not pity her."
(Deuteronomy 25:11-12)

Amazing! If Islam asks for a light beating in case a wife degrades herself by indulging in open-lewdness and thus showing disloyalty to her husband they say it’s inhumane and barbaric! But if the poor wife in her love with her husband tries to save the life of her husband they say cut off her hand, don't pity her! Amazing! Even if she gets hold of that man by taking him by his secrets, still she is trying to protect her husband not going into open lewdness anyway.

You remember what Jesus (PBUH) said;

"You blind guides, you strain out a gnat, and swallow the camel." (Mathew 23:24)

So, the fact is that Islam allows this only in extreme conditions and that also not without restrictions. Infect Islam allows it only in the collective interest of the whole society and its more of a psychological punishment then a physical one. And those who make an issue out of it are ignorant of Islam's high moral and ethical standards while Biblical standpoint lacks reason. What Islam allows cannot be even termed as beating in ordinary sense but what Bible allows must be termed as wife butchering.

The ‘Civilized’ West, wife beating and ‘honor killings’:

Women suffer more violence at the hands of their spouses/partners in non-Muslim countries.

‘In Australia, Canada, Israel, South Africa and the United States, 40-70 per cent of female murder victims were killed by their partners.’ (Krug, E. et al. eds. 2002, World Report on Violence and Health. Geneva: WHO. Online Source)

According to a report for US Department of Justice, Bureau of Justice Statistics, in US ‘Intimate partner violence made up 20% of violent crime against women in 2001.’ (Online Source)

Many would love to raise finger at Islam because of the reports of ‘honor killings’ from remote corners of Muslim lands. Being killed by one spouse is called ‘honor killing’ when it comes to Muslims and a less violent term ‘domestic violence’ is used when it comes to New Yorkers. According to a 2008 report from Department of Health and Mental Hygiene titles as ‘Intimate Partner Violence against Women in NYC’ reveals that between 2003 and 2005 nearly half of all women murdered were victims of their partners.

Now what’s the cause of all this above? Not Islam of course!

INDEED ALLAH KNOWS THE BEST!