I love this quote from A.K. Mozumdar:
"There is a vast difference between the mortal and the spiritual planes of mental action.
[Joel Goldsmith referred to them as the 'mental plane' and the 'spiritual plane;' this is terminology which works a little better for me.]
In the one, we use our mind in our conception of perfecting a certain temporary result, and in the other, we use our mind to realize That which is permanent and above any result."