I did address this issue in some depth in my Undercroft blog here
if you have access to that network.
I also discussed this issue in my 9-Sense Halloween interview with Adam Cambell (link in my signature here).
I should also mention that there is an entire members-only forum here that is devoted to Greater Magic as well.
Here I will offer a shorter overview of the issue.
Expecting you to not even think about the desired outcome after the ritual is not what the Doktor was discussing. That would not work any better than the success you would find if told "Don't think of green monkeys!"
Clearly what the instructions are conveying is to exert the mental discipline to suppress the "anxiety" of expecting FAILURE.
This intent of not undercutting your ritual efforts is also found embodied in the 7th Satanic Rule of the Earth as listed here:
Acknowledge the power of magic if you have employed it successfully to obtain your desires. If you deny the power of magic after having called upon it with success, you will lose all you have obtained.
There are psychological principles that are in operation here and these are critical. "Faith" is not one of them. Anxiously expecting failure is.
Satanism is very pragmatic. Faith is not involved. However tried and true methods are.
It is similar to starting a car. It is a matter of following the instructions to insert the key in the ignition and turning it. It is not an issue of "faith". It is entirely an issue of following the instructions.
Also, the Doktor was quite clear in The Satanic Bible
that this was a "primer" in basic magic, not a graduate course of study.
In the beginning it is necessary to suppress the fear of failure. With successful experiences you gain confidence and can dispense with such concerns.
Start the car enough times and you will have confidence it will start. This is not "faith". This is the result of successful car-starting.
In the end Greater Magic is exactly like swimming. The only way to understand it is to get into the water.