The heart losing fear begins to know peace, the peace that they say passeth understanding. It cannot abide in peace. That is the gift of the heart. And the mind no matter how sharp it gets cannot deliver peace unto the whole of you. It is only through the doorway of the heart that you unite with peace within inside of you.
Peace is the property of the heart.
When fear begins its crucifixion within you you feel a shift happening in all four bodies. At first it feels that you do not know who you are anymore. Some have called this the burning up of the causal body. They have called this the soul merge beginning and the individuated God Presence claiming dominion over the soul as it continues to claim dominion over the personality. Wrapped in the arms of the monad the soul merges into the monadic part of you.