If you lie unless you have no conscience at all you'll often lose sleep because of your fears of being found out. Your worry and your guilt will keep you awake. A good night's sleep is one of life's many pleasures and honest people sleep better. They know at least at some level when you're being fake. If telling lies is your modus operandi, you know that these people will often see though your fa ade.
Relationships are the jewels of our lives.
Some would argue that relationships ARE our lives. And breeches in trust are the death knell of relationships. When trust is gone, there is no foundation upon which to build. Relationships lacking in trust seem hollow and shallow. They lack joy.