Our Heavenly Father has asked us to serve one another. By serving each other we show our Father in Heaven through our actions that we love Him and our fellow brothers and sisters. My dad and I talked on occasion about the good feeling that comes after serving someone else. Why is that?? Why do you feel so good after you've used your time and your effort to help someone else? It is because the Holy Ghost will testify to you that you have done the right thing.
"And behold, I tell you these things that ye may learn wisdom; that ye may learn that when ye are in the service of your fellow beings ye are only in the service of your God."1 -King Benjamin