Today, I read 1 Nephi 2:10. I decided to study footnote b: TG Dependability. After reading several of the references, I came to D&C 82:24, which reads: "For even yet the kingdom is yours, and shall be forever, if you fall not from your steadfastness. Even so. Amen."
We always hear people mentioning "endure to the end" as one of those "Sunday School" answers. But it really is the key!! As long as we're trying, "the kingdom is [ours]." That's a wonderful promise!