The theme of revelation continues with Nephi declaring that the Spirit hath carried him away upon exceedingly high mountaintops. Not only are mountaintops a common symbol for a meeting place between man and Jehovah, but Nephi’s vision of the Tree of Life was part of just such a meeting with the Spirit in the mountaintops.
Nephi, therefore, asks the rhetorical question. Why, if he has had such marvelous experiences, does he sometimes still feel sad? It is a question that has been asked by so many of God’s children, both before and since. Nephi is not denying that he has those feelings, only that they are balancing, or even potentially overpowering experiences, that should provide him the hope to recover from the depths of sadness.
Nephi declares that his knowledge should keep him from sin, but it does not. Again, all who read his words understand that feeling. We too know better, and do not always do the good that we know we should do.