I understand that liers cannot be trusted

I understand that liers cannot be trusted...
Coz they can tell so many lies and one covers another one,
and they never let other know what is really happening,
what really they are thinking, doing,
coz they know that the real things are not allowed to
discover, to tell,
why? why they lie? coz this is the characteristic, and also the
habit,
when a lie appears, another coming, and other, another..........
their minds are very complicated, sometimes terrible,
dont even try to get involved in or try to read their minds, or
will get crazy,
I cannot build up any confidence on a lier as well, I
understand.
Can any one tell me how to trust them?