Answer:
Learning how to lie can give you an advantage over others, help you better your life, and make people around you more honest – all without doing any sort of damage to anyone. But a generally truthful world is a good thing: lying diminishes trust between human beings: if people generally didn't tell the truth, life would become very difficult, as nobody could be trusted and nothing you heard or read could be trusted - you would have to find everything out for yourself.
Have a great day! :D