When I was younger and my mom wanted us to do something she would start singing the primary song, "When my mother calls me, quickly I obey..." And ya know, we would always come running. At least that's how I remember it... She might recall things differently.
Obedience is the first law of heaven and therefore is an important concept for us to understand. There are many reasons people choose to obey God and few of them are:
1) Obedience out of fear.
2) Obedience in hopes of a reward.
3) Obedience out of love.
The way in which we obey is perhaps more important than obedience itself. Moroni quotes his father, saying, "a man being evil cannot do that which is good; for if he offereth a gift ... unto God, except he shall do it with real intent it profiteth him nothing." Take Laman and Lemuel, for example, they did many of the same things as Nephi but with a completely different attitude and we see how that turned out..
To finish off my thoughts, I really like what Nephi writes as he finishes his record in the Book of Mormon, "for thus hath the Lord commanded me, and I must obey." Ultimately, being obedient to God should be a part of who we are, not because are afraid of Him or the persuasions of man but because of our gratitude and love for Him.