Only accepted religion is Islam

And whoever seeks a religion other than Isl‚m, it will never be accepted of him, and in the Hereafter he will be one of the losers. (Al-Imran, 3:85)

Surely, those who reject Faith (disbelieve in All‚h and in Muhammad صلى الله عليه وسلم as being All‚hís Messenger and in all that which he صلى الله عليهوسلم has brought from All‚h), neither their properties, nor their offspring will avail them aught against All‚h. They are the dwellers of the Fire, therein they will abide. (Al-Imran, 3:116)
Narrated Abu Hurairah رضي الله عنه: All‚hís Messenger صلى الله عليه وسلم said: "By Him (All‚h) in Whose Hand Muhammadís soul is, there is none from amongst the Jews and the Christians (of these present nations) who hears about me and then dies without believing in the Message with which I have been sent (i.e. Isl‚mic Monotheism), but he will be from the dwellers of the (Hell) Fire." (Sahih Muslim , the Book of Faith, Vol.1, Hadith No.240).

American students have asked me to define Islam as mentioned in 3:85 above. Likewise, at Stanford University questions came up:

1) How does one define a believer?
2) What is the definition of the word Kafir?
3) Does Hadith over rules Quran?
4) How many ayats are abrogated in the Quran?

Do you have answers to the above 4 questions? This is what is needed before giving anyone the electronic Quran.