Not true. Scripture came on down through the generations and Jesus fulfilled it. Proven. He said the temple would be destroyed, it was. Proven. He brought His words back to the apostles mind, as promised. Proven. He brought Himself back from the dead. Proven. He lives in millions of people today. Proven. His word did live on, and since it is proven Jesus is God, they will live on.
In your head, maybe. Not out here.
Jesus didn't fulfill the prophecy perfectly, and nothing existed to prevent people from rewriting his details to match any prophecy better. People lie, people exaggerate, and people forget the true details, and witnesses die. One has to assume biblical authors are actually reliable sources in order to even consider the possibility of truth in the bible, and there is nothing to suggest that they are particularly trustworthy.
All buildings crumble eventually, and self-fulfilling prophecy. Did Jesus predict it, or did the event occur and then someone claimed that he predicted it? Who knows?
Jesus's resurrection is far from proven, and details in regards to it contain some of the most concentrated contradictions in the New Testament. Nearly every detail about it, from whether or not the tomb was open, to how many witnesses, has 2-3 different versions. Oh, how did Judas die? Well, he hanged himself. Bible approves. Well, his body burst like a gorey water balloon. Bible also approves.
His word hasn't lived on FOREVER yet. This is a situation that is unprovable; we would have to wait a literal eternity to see if it was true, which is time we do not have.
It isn't in my head, open the bible and look for yourself, these contradictions are something a child could notice.