The big word in your question is "if." If your scenario is true, then Jesus lied to us. I, for one, don't believe that Jesus was a liar, or crazy, or a charlatan. Jesus is the one who made the claims about being the only Way to heaven, the source of this claim is the Bible, not Christian opinion. Your claim that these two religions are the same means that one is defining the other, and in this case, you are defining Christianity according to Krishna. If you are going to allow Christianity to have its own voice in the dialog of world religions, at a bare minimum you need to allow it to make its own claims. Since Hinduism in general and followers of Krishna specifically claim that all paths lead to the same goal, what you are saying is that Krishna is right and Jesus is wrong; because Jesus most emphatically denies that Christianity is one path among many. And really, isn't your question the same as asking, "What if Pixar and the Federal reserve have the same mission?"
For the record, there is not a single verse in the Bible that could lead you to the conclusion that Christianity is about "self realization."