Deceit, deception, hypocrisy, artifice, cheating. 

To put it simply, lies.

Trust, the one thing that lies can destroy so easily. Yet, trust is also what causes lies to be believed. 

Without trust, the world would be made up of paranoia and skepticism. The only liars who would succeed in such a world are those who can manipulate feelings, both the feelings of the liars and the lied. 

However, our world isn't like that. There are many who are too innocent and gullible to believe in lies. Thus, these liars who manipulate feelings have everyone under their control. These manipulators of feelings could also be known as masters of deceit.