God has to be searched and invoked in the secret of a rational soul, which is called the interior man.
(De magistro 1)
I shall know you, you who know me. Virtue of my soul, go deep into it and make it fit for you, so that you may have it and possess it, without stain or wrinkle.
No one is able to reach God without flying over oneself.
(In Io. Ev. XX, 8)