Fear makes itself felt on every level:  physical (sensations), emotional (feelings) and psychological (beliefs).   Physically, we may feel vulnerable to attackers or disease.  Emotionally,  we suffer from loneliness, shame, guilt, fear or abandonment, jealousy, the list goes on and on.  Psychologically, not being believed or being given the silent treatment are tormenting for most people.  These are just some examples of how the ego uses fear.

To utilize the ACIM forgiveness practice, we have to allow our worst fears to surface.  Fears that we will be hated, rejected and maligned  by others if we speak our truth, make a mistake, or just be ourselves.  This is the deep existential guilt every human carries at our core, because we believe God wants to punish us.  And that's scary! 

"Bring, therefore, all your dark and secret thoughts to Him, and look upon them with Him.  He holds the light, and you the darkness.  They cannot coexist when both of You together look on them.  His judgment must prevail, and He will give it to you as you join your perception to His."

The Holy Spirit, sometimes referred to as the Voice for God, only "judges" us with Love.  He knows us for What we really are--an extension of God's Love and He reminds us that we are always included in that Love.  For some of us, it is a great relief to give everything to the Holy Spirit.  And for some there is terrible disappointment when we don't get the results we hoped for.  Notice if you're harboring hopes.  That means you're choosing the ego as your teacher and telling Spirit how to do His job.  All we're asked to do is give every secret, open every door and bid Spirit to enter our darkness and lighten it away.