It opens wide the door to the dismissal of all Christian claims. Let's face it, the skeptics have a legitimate complaint if Jesus did not do something that He said He would . They are more than aware of the dilemma that nonoccurrence presents for the Christian Church and the impossibility of escaping it without being disloyal to Christ. The fact is, Jesus made clear, concrete, future predictions about his coming in glory that seemingly did not come to pass. Or so we've been told.
Criticism concentrates on that point.
And people have attacked the credibility of Jesus. Maybe some church fathers made a mistake. Maybe our favorite theologians have made mistakes. I can abide with that. I can't abide with Jesus being a false prophet, because if I am to understand that Jesus is a false prophet, my faith is in vain.