Allah said about the Qur'an: "A Book whereof the verses are explained in detail, a Qur'an in Arabic for people who know."
The Praise is for Allah, the one who has honoured us with the Qur'an, and chosen for us the noblest of languages, and the peace and the blessings be upon the best one of the ones who articulated themselves in Arabic, and the most-preferred from the servants of Allah, Our Prophet Muhammad (peace be upon him), and his family and his distinguished companions.
The Arabic language is the language of the Noble Qur'an, and with it, the Qur'an was revealed upon the seal of the Messengers, so attention to the Arabic language is to have attention to the Book of Allah the Most High and the studying and the practising of it helps in the understanding of the Noble Book of Allah and the narration of the master of the Prophets, Muhammad (peace be upon him). It is also the language of our esteemed Islamic law (ash-Shari'ah), so when we defend it we are not proceeding on a path of nationalism or racism or culturalism, but in fact we are defending the language of our religion (way of life) and it is the cloak of our Islamic Civilisation.
As such, Shaykh ul-Islam Ibn Taymiyyah said: "The Arabic language is from the Religion, and the knowledge of it is an obligation. For surely the understanding of the Qur'an and the Sunnah is an obligation, and these two are not understood except with the understanding of the Arabic language, and whatever obligation is not fulfilled except by certain steps then those steps themselves become obligatory (to fulfil the initial obligation)." [The Necessity Of The Straight Path by Ibn Taymiyyah (1/470)]
So then the knowledge of the Arabic language is essential for every Muslim so that he can perform his religious acts of worship and he can be proficient in the recitation of the Noble Qur'an. Allah says in His Book (which means):
"Verily we have sent it down as an Arabic Qur'an in order that you may understand."
And likewise the Most Glorious said (which means):
"And thus We have inspired unto you (O Muhammad) an Arabic Qur'an that you may warn the mother of the towns (Makkah) and all around it."
And The Exalted said (which means):
"And truly this (the Qur'an) is a revelation from the Lord of the 'Alamin (mankind, jinn and all that exists), which the trustworthy Ruh (Jibril) has brought down upon your heart (O Muhammad) that you may be (one) of the warners, in the plain Arabic language."
And He the Most High also said (which means):
"A Book whereof the verses are explained in detail, a Qur'an in Arabic for people who know."
So from these verses we see why the Arabic language has reached its station due to the fact that Allah has guaranteed its protection when He undertook upon Himself the preservation of this Noble Qur'an since it is the language of that Book.
The Most Merciful said (which means):
"Verily! It is We who have sent down the Reminder (i.e. the Qur'an) and surely We will guard it (from corruption)."
Despite this, many of the Muslims are content by spending their whole lives reading a translation of the Qur'an and so depriving themselves of the miracle of the Speech Of Allah. Also a translation implies a human factor, which goes against the very essence of the Book of Allah. Also, the person who does not know Arabic, will have added difficulty in his concentration during his prayers and also in his understanding of the Sunnah. This is because a language is just not a collection of words which can readily be translated into another language but is a whole way of thinking.
Dr. Muhammad Taqi ud-Din al-Hilali (Translator of the Noble Qur'an) writes:
"It is a pity that many nations are only satisfied in the translated meaning of the Qur'an and Prophet's Sunnah instead of studying the (true) Arabic text of the Qur'an and Prophet's Sunnah. For this reason they are divided into various sects (due to the lack of knowledge about the religion of Islam) e.g. as regards to the ways of religious education, etc. so they are plunged in differences, which was prohibited by Allah. If the translation of the meaning of the Qur'an is meant for the above said purpose then it is a real mischief-doing, and an evil action and is against what was brought by Allah's Messenger (peace be upon him) and also against the opinions of the early present day religious scholars. All the religious scholars unanimously agree that the Qur'an and the Sunnah should be taught in the language of the Qur'an (i.e. Arabic language). So did the early religious scholars of the Muslim nation when they conquered different countries.
"Translations are mainly meant for informing the people who have not yet embraced Islam to make clear to them the principles of Islam and the teachings of Muhammad (peace be upon him) and to know its exact facts. When they reach this state and Allah has blessed them with Islam, they must take the Qur'anic and the Messenger's language (i.e. Arabic) as the only language to understand Islam. May Allah's mercy be on Shaykh 'Umar Uzbek, a great Turkish man, who strove for Islam in Uzbekistan under the Russian government, after his long fight against the enemies of Islam with fire (iron) and tongue (speech), he took refuge in Afghanistan at Kabul, where the government honoured him. I met him there in 1352H (approx. 1932CE) i.e. nearly 40 years ago, and he had vowed to Allah that he will never speak to a relative or anybody else except in the Qur'anic and Messenger's (Arabic) language. His wife sent a man for me to intercede for her to him that he should speak with her and her children in the Turkish language even for an hour everyday. So when I spoke to him about it, he said: 'Russians had compelled us to learn perfectly the Russian language (by force), so we learnt it. And unless they knew that the learning of the Russian language will make the person who learns it, follow their ways of thinking, characters, and their traditions, they would not have forced anybody to learn it.' He further said to me, 'I have vowed to Allah long ago not to speak except in the language of the Qur'an and Sunnah (i.e. Arabic) and I do that only for Allah's sake. If my wife and children desire to enjoy speaking with me, they should learn the language of the Qur'an and of the Prophet (peace be upon him) (i.e. Arabic) and I am ready to teach them the Qur'anic language whenever they desire that.' "