Moshe's task at the end of his life was to inspire and motivate the nation that they be prepared to inherit the land. The Alshich says that Israel was a gift given to the Jewish people. It became an inheritance when they observed the Mitzvot, which was the ultimate purpose of their receiving Eretz Yisrael. Moshe also addresses the question of fear. He was aware that the Jewish people were entering a place with nations far greater than them. Again, the Alshich points out that there are times when fear is very rational. If one sees he's greatly outnumbered, he has a legitimate reason to be afraid. On the other hand, fear can come out of nowhere and one's fear is really based on one's personal feelings of inadequacy. Whatever the case may be, Moshe is telling the people that they have no reason to express fear of any kind as long as Hashem is close to them. When we have faith, we feel Hashem's protection and we realize that there is nothing to fear.