“Above all, don’t lie to yourself. The man who listens to his own lie comes to a point that he cannot distinguish the truth within him, or around him, and so loses all respect for himself and for others. And having no respect he ceases to love.” ― Fyodor Dostoevsky

A toxically shamed person is divided within himself and must create a false-self cover-up to hide his sense of being flawed and defective. You cannot offer yourself to another person if you do not know who you really are.
John Bradshaw • Healing the Shame That Binds You
The deception of others is nearly always rooted in the deception of ourselves.
AA World Services Inc • As Bill Sees It
“By a lie a man throws away and, as it were, annihilates his dignity as a man. A man who himself does not believe what he tells another … has even less worth than if he were a mere thing. … makes himself a mere deceptive appearance of man, not man himself.”
Immanuel Kant
I mean, it's not the fact that they're lying; one can always forgive a man for telling lies; lying's a harmless activity, because it leads to the truth.