What can interfere with the awareness of reality is the belief that there is something there.
The picture of your brother that you see means nothing. There is nothing to attack or to deny; to love or hate, or to endow with power or to see as weak. The picture has been wholly cancelled out, because it symbolized a contradiction that cancelled out the thought it represents. And thus the picture has no cause at all.
Who can perceive effect without a cause? What can the causeless be but nothingness? The picture of your brother that you see is wholly absent and has never been. Let, then, the empty space it occupies be recognized as vacant, and the time devoted to its seeing be perceived as idly spent, a time unoccupied.
An empty space that is not seen as filled, an unused interval of time not seen as spent and fully occupied, become a silent invitation to the truth to enter, and to make itself at home. No preparation can be made that would enhance the invitation’s real appeal. For what you leave as vacant God will fill, and where He is there must the truth abide.
T-27.III.4