Victory over our lower nature is always a little shaky. It is like the conquest of one country by another: no one can be sure how long it will last.
The day is bound to come when the conquerors rest on their laurels and the conquered rise up and take their revenge. This is what happens with our lower nature: even if, in certain circumstances, you manage to conquer some of its manifestations, final victory is never assured.
From one moment to the next, it can rear up and start bucking and kicking, and you find yourself flat on your back! So what is the solution? The only thing to do is to implore your divine nature, the Christ principle, to come and dwell within you.
Then, instead of being like a conqueror who is never sure of victory, you will have a powerful ally to count on.
Even when you are tired and less alert, this ally will continue to keep your lower nature in check.