In reading the book 'The Heart of Christianity' by Marcus Borg, he makes the point about deception in regards to an 'open' or 'closed heart':
A closed heart affects the mind, the reasoning process itself. Rather than the mind being in charge of this deeper layer of the self, the heart controls the mind. The heart can even deceive the mind in the process we call "rationalization," that is, self-interested self-justification. We often believe our own deceptions. The phenomenon of self-deception (always easier to recognize in others than in ourselves) is fascinating: there is something "in me" that can deceive me. Thus the closed heart is associated with lack of understanding and a darkened mind.
I found this insightful as well frightful. It can have implications in regards to true love, to fundamentals in a personal faith. All that is near and dear.
It caused me to pray.:
Lord give me an open heart
Where motives are pure
Where yes means yes
Not only for me,
but for those around me.
Yes an open heart.