One of the most widely quoted scriptures in the entire Book of Mormon is the statement of King Benjamin: "when ye are in the service of your fellow beings ye are only in the service of your God." (Mosiah 2:17.) In this statement Benjamin includes the essence of the two great commandments that were later enunciated by the Savior: (1) that we should love God with all our heart, soul, and mind, and (2) that we should love our neighbors as ourselves. (Matthew 22:37-40.)
If we truly love God and keep his commandments, we will serve our brothers because he has commanded us to love them. Therefore, as King Benjamin indicates, when we are in the service of our fellow beings we are only in the service of our God.