[21].Al-Anbiya' [The Prophets]: Ayat 34-35

Ayat 34. And We granted not to any human being immortality before you (O Muhammad [SAWW](PBUH), then if you die, would they live forever?

Ayat 35. Everyone is going to taste death, and We shall make a trial of you with evil and with good, and to Us you will be returned.

[Tafseer] We granted not to any man before thee permanent life (here): if then thou shouldst die, would they live permanently? Life on this planet without death has not been granted to any man. The Khidhr legends are popular tales. His life without death on this earth is nowhere mentioned in the Qur'an. The taunt of the Unbelievers at the Holy Prophet was therefore futile. Could any of them live without death at some time or other? Could they name any one who did? Every soul shall have a taste of death: and We test you by evil and by good by way of trial. to Us must ye return. The soul does not die, but when it separates from the body at the death of the body, the soul gets a taste of death. In our life of probation on this earth, our virtue and faith are tested by many things: some are tested by calamities, and some by the good things of this life. If we prove our true mettle, we pass our probation with success. In any case all must return to Allah, and then will our life be appraised of its true value. 

Hazrat Tamim bin Aus Ad-Dari (May Allah be pleased with him) reported: The Messenger of Allah [SAWW](PBUH) said,"Ad-Deen is sincerity". We said: "For whom?'' He replied, "For Allah, His Book, His Messenger and for the leaders of the Muslims and their masses". 

[Muslim Book 01, Chapter 24, Hadith # 098] 

Lesson : as mentioned above in Surah Al-Anbiya' Ayat 35."We shall make a trial of you with evil and with good" This Hadith stresses the importance and merits of general sincerity. Sincerity for Allah here means that one must have true faith in Him and He should be worshipped with full devotion and sincerity. Sincerity for the Qur'an means that one should confirm its truth with one's full heart and mind, recite it regularly, act upon the injunctions contained in it with meticulous care and strictly avoid its misinterpretation. Sincerity of the Prophet (PBUH) means sincere confirmation of his Prophethood, faithful obedience of his orders and adherence to his Sunnah. The goodwill of the Muslim rulers stands here for co-operating with them in their lawful orders and obedience of their such orders which are free from any trace of sin. If they deviate from the Straight Path they should be persuaded to turn to virtue. One should not revolt against them unless they commit infidelity. The goodwill of the Muslim masses means that one should work for the betterment of their life in this world and the Hereafter. They should be provided the right guidance, induced to perform good deeds and deterred from evils.