God does not judge us like a college professor who fails you if you score below some prefixed mark or passes you after you have earned enough credit. I am sure that in some cases there is no question that the soul will go to heaven or hell. Anyway, I believe God will consider many factors at judgment time. If you are right on the borderline, he may just let you pass. The best policy is to love the Lord as much as possible and we don't have to be concerned about how we'll be judged.