People think that a liar gains a victory over his victim.
What I've learned is that a lie is an act of self-abdication, because one surrenders one's reality to the person to whom one lies, making that person one's master, condemning oneself from then on to faking the sort of reality that person's view requires to be faked. And if one gains the immediate purpose of the lie -- the price one pays is the destructions of that which the gain was intended to serve.
...there are no white lies, there is only the blackness of destruction, and a white lie is the blackest of all.
Ayn Rand Atlas Shrugged