...and die not except in a state of Islam. (Quran-3:102)

What is Islam ?

A long and vey well known Hadith-e-Jibreel about Islam, Eeman, Ihsan:

On the authority of Umar (RA), who said:

"While we were one day sitting with the Messenger of Allah, sallallahu 'alayhi wasallam, there appeared before us a man dressed in extremely white clothes and with very black hair.  No traces of journeying were visible on him, and none of us knew him.

Sitting down before the Prophet, leaning his knees against his, and placing his hands on his thighs, he said, "Tell me, Muhammad, about Islam (Submission)."  Messenger of Allah, sallallahu 'alayhi wasallam, replied;

"Islam is that you should testify that; There is no deity save Allah and that Muhammad (pbuh) is His Messenger,   That you should perform Salah (Ritual prayer),  Pay the zakah,  Fast during Ramadan,  And make the pilgrimage to the House if you are able to go there."

Said he (the man), "You have spoken truly."  We were astonished at this, questioning him and then declaring that he had spoken the truth.

"The man then said, "Tell me about Eeman (Faith)."  He (the Messenger of Allah - pbuh) answered;

"It (Faith) is that you believe in Allah and His angels and His Books and His Messengers and in the Last Day, and in Fate (Qadar), both in its Good and in its Bad aspects."

He (the man) said, "You have spoken truly."

Then he (the man) said, "Inform me about Ihsan."  He (the Messenger of Allah) answered;

"It (Ihsan) is that you should serve Allah as though you could see Him, for even if you do not see Him, He sees you."

He (the man) asked, "Inform me about the Hour."  He (the Messenger of Allah - pbuh) said,

"About that (the hour) the one questioned knows no more than the questioner."  So he (the man) said, "Then, inform me about the signs thereof (i.e. of its coming).  Said he (pbuh),

"They are that the slave-girl will give birth to her mistress, that you will see the barefooted ones, the naked, the destitute, the herdsmen of the sheep (competing with each other) in raising lofty buildings." Thereupon the man went off.

I (Umar - RA) waited a while, and then he (the Messenger of Allah - pbuh) said, "O Umar, do you know who that questioner was?"  I replied, "Allah and His Messenger know best."  He said, "That was Jibreel who came to teach you your religion."