Q:

Is Arabic necessary in answers?

In answers like III-AK-III's, when they provide Quranic verses and hadith, they include Arabic and then the English translation. Is this really necessary?
The only time I could think of when it would be necessary is when a question is asked about the Arabic in the Qu'ran such as What does كُفُوً mean in Surah Ikhlas?.
Question: Should answers contain unnecessary usage of Arabic?
In this answer, it contains a Arabic paragraph which should be translated in English as this is an all English language site.

A:

Should answers contain unnecessary usage of Arabic?

The use of "unnecessary" seems to imply what kind of answer you aim to get to this question.  But...
We don't want to obstruct answerers.  At math.SE, an expert user liked to use taglines against the site's policy.  He left.  He's still around at MathOverflow (here) using taglines against the site's policy.  The moral is that getting high-quality answers is a top priority, and we don't want to obstruct that.  So...
What's the big deal?  It doesn't seem to be as if using Arabic is a major problem harming the site.  In fact...
Who says it's unnecessary?  If an answer contains Arabic, the author probably put it there for a reason, e.g., because it's more authentic or they don't fully trust a translation.  This should be respected too.
Having Arabic may also add to an answer in other ways:

"Eye candy".  Basically, it makes the post look nice.
It can break apart English text, and provide a visual aid for when quotes are being made.
It may be useful to readers who can also read Arabic.

A:

Using Arabic specifically in Quran and Hadeeth can never be deemed unnecessary.
First, Quran and hadeeth were said in Arabic, so when quoting them, it is best that we primarily use Arabic if we can, and then translate the Arabic. This will keep Allah’s words and His Prophet’s words intact and give Arabic speakers and nonArabic speakers who have memorized Quran a direct access to the actual words used.
Second, meaning may slightly vary from one translation to another, so we cannot say Allah said so and so when He has not said it, but the tafseer/interpretation leaned towards this meaning or that.
Third, having the original Arabic text will allow others to copy a hadeeth and paste it into their search engine of their desired hadeeth database to get the translation they are used to, instead of having to battle with different translations. With an ayah, it is much easier, since people can reference the surah and ayah number; however, people can still copy the ayah and paste it into the search slot in the Quran application.
Last, there is nothing more powerful than seeing Allah’s words quoted. This same effect is not derived from seeing a translation. 

