fChrist (pbuh) cannot be said to have failed in his mission

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 God says:

[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)