Think not you understand anything,
until you pass the test of perfect peace,
for peace and understanding go together,
And can never be found alone.
The Test of Truth
Nothing real can be threatened.
Nothing unreal exists.
Herein lies the peace of God.
~A Course In Miracles
No one really sees anything. He sees only his thoughts projected outward. The mind’s preoccupation with the past is the cause of the misconception about time from which your seeing suffers. Your mind cannot grasp the present, which is the only time there is. It therefore cannot understand time, and cannot, in fact, understand anything.
The one wholly true thought one can hold about the past is that it is not here. To think about it at all is therefore to think about illusions. Very few have realized what is actually entailed in picturing the past or in anticipating the future. The mind is actually blank when it does this, because it is not really thinking about anything.
~From Lesson 8 of A Course in Miracles