Christ (pbuh) cannot be said to have failed in his mission. God supported him with astounding miracle and convincing arguments. Whatever distortion has befallen the scripture preached by Christ, it must have happened after his ascention to heaven. Failure and disintegration are the works of the followes who fell a prey to whims and... caprice. In this connection
[And (remember) when God will say (on the day of reurrection): ‘O Jesus, son of Mary! Did you say unto men: ‘worship me and my mother as two gods besides God?’ He will say: ‘Glory is to You! It is not for me to say what I had no right (to say). Had I said such a thing, You would surely, have know it. You know what is in my inner-self though I do not know what is in Yours; truly You, only You, are the All-Knower of all that is hidden (and seen). Never did I say to them aught except what You (God) did command me to say: worship God my Lord and your Lord. And I was a witness over them while I dwelt amongst them, but when you took me up, You were the Watcher over them; and You are a Witness to all things’.”] (Holy Qur’an: 5: 116-117)
 God says:

Morsy Aboelfwares There is no doubt that all prophets (peace be upon them), beginning with Adam and ending in Muhammad, preached one religion—the worship of God alone and disregarding all other powers. This is something advocated by Islam. God says: “Truly..., the true religion with God is Islam” (Holy Qur’an: 3: 19). About Abraham (pbuh), God says: “Abraham was neither a Jew nor a Christian, but was a true Muslim (hanif: monotheist—a worshipper one God alone) and he was not a mushrik—a polytheist” (Holy Qur’an: 3: 67). On the question of the disciples of Jesus, God says: “And when I (God) inspired al-hawariun (the disciples of Jesus) to believe in Me and My Messenger, they said: ‘We believe. And bear witness that we are Muslims’.” (Holy Qur’an: 5: 111). Prophet Muhammad (pbuh) confirmed this in his saying: “Prophets are paternal brothers; their mothers are different, but their religion is one.

إِنَّ الَّذينَ قالوا رَبُّنَا اللَّهُ ثُمَّ استَقٰموا تَتَنَزَّلُ عَلَيهِمُ المَلٰئِكَةُ أَلّا تَخافوا وَلا تَحزَنوا وَأَبشِروا بِالجَنَّةِ الَّتى كُنتُم توعَدونَ ﴿ فصلت : 30

“Verily, those who say: ‘Our Lord is Allah (Alone),’ and then they stood straight (followed Islam truly), on them the angels will descend (at the time of their death) (saying): ‘Fear not, nor grieve! But receive the glad tidings of Paradise which you have been promised!’” {Qur'aan, 41:30

There is no compulsion in religion. Verily, the Right Path has become distinct from the wrong path. Whoever disbelieves in Evil and believes in Allâh, then he has grasped the most trustworthy handhold that will never break. And Allâh is All-Hearer, All-Knower.
Quran (2, 256)

Whoever works righteousness, whether male or female, while he (or she) is a true believer verily, to him We will give a good & pure life (in this world with respect) and We will bestow on such their reward according to the best of their actions (i.e. Paradise in the Hereafter).
Quran(16, 97)

"Say (O Messenger): I do not ask of you any reward for it (the message and mercy from God) but love for my Ahle bait;"

(Surah Shura 42:23)

mircle knocking the stars in the quran

http://youtu.be/TCRyV7EVfy8

‎"By Him (Allah) in Whose Hand Muhammad's 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. tawheed), but he will be from the dwellers of the (Hell) Fire Hadith -Saheeh Muslim, vol. 1, no. 284

‎"By Him (Allah) in Whose Hand Muhammad's 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. tawheed), but he will be from the dwellers of the (Hell) Fire Hadith -Saheeh Muslim, vol. 1, no. 284