One of the biggest underlying reasons for lying is fear. Fear of rejection, fear of what the truth uncovers, fear of vulnerability.
The truth hurts often times and we humans don't like pain. But the flip side of that is honesty is always a better foundation, even if it's painful. Without honesty/communication you let "things" take on a life of their own giving it power to effect things and cause things that might actually be false to exist. As in relationships where you don't/can't speak the truth. Not saying something where correction or communication is needed, just gives power to falsehoods. A whole world of falsehoods can develop that actually cause nothing but things that shouldn't exist or they should be completely dismantled.
The truth hurts, but it's worth having the hurt in order to be perusing something healthy and valuable. Lies are a house if cards. 4951