Matthew 24:13 But he that shall endure unto the end, the same shall be saved.
Some would have you to believe that you must endure unto the end to go to Heaven. If one was to take this verse out of context, I can see where one could twist it to mean that. But if you leave this verse in context, you will see that it does not mean that at all. The end to which it refers is not the end of your life; the context is talking about the end of that time. Did Paul endure unto the end? Did Peter? Did James? John? Any of the apostles? No, all of them died before the end of that time. Also, the object that is being saved is not the soul and spirit; the context is talking about saving the flesh (verse 22).
We are confident that he which began a good work in us will perform it until the day of Jesus Christ. We know that we have been sealed unto the day of redemption. We know that he has given unto us eternal (never-ending) life.