It says in Mishlei “for with strategies you should make war for yourself.” We know how many tricks and strategies a person uses for his self-honor and to make money. How much more so he needs to find ideas in his soul and strategies to fight the obligatory war against the evil inclination.
Behold, for every good thing that a person wants to do, the Satan stands on his right-hand side to dissuade him and to prevent good from its owners. How much more so does he try to prevent him from study of Torah for our Sages have said that if a person does not succeed in conquering the evil inclination, he should be busy with Torah. Likewise they said “If this repulsive thing (the evil inclination) wounds you, pull him to the Beis Medrash. If he is made of stone, he will be dissolved and if he is made of iron, he will explode.”
It follows that the evil inclination will use doubly touigh persuasion tactics not to be busy with Torah and not to go to the Beis Medrash. It follows that the well known idea suggested to man is that he should employ strategies like a soldier of war. He should present himself as though he does not want to fight until the time comes when his enemy gives up on him and he can live alone and in peace. After this, suddenly he will pounce on him and wound him mortally. This is what King David used to do for all day he would say “I am going to such and such a place or to such and such a house” and through this his inclination would leave him and suddenly his feet would carry him to the Beis Medrash. Therefore it is the custom of the righteous to say a little and do a lot. If a person thinks or says “I will learn this and this” or “I will do this and this good deed” the inclination will stand up with all his strength and deploy upon him many delays and many preventions to prevent him. Therefore, if his heart has stirred with an idea about a good deed – he should immediately and hurriedly translate the good thought to deed and hurry himself when he is able.
There is another great fence and great strategy and that is as the Sages have said “A person should always busy himself with Torah and Mitzvos even if it is not for the sake of Heaven for through this he will come to doing them for the sake of Heaven.” When the evil inclination sees one who is busy (with a mitzva) not for the sake of heaven but to receive reward for his work, he leaves him and says “this is one of ours for he does not serve G-d but serves himself for he does everything in order to get a reward.” In truth the virtue of Torah is the antidote for the evil inclination and the commandments of G-d are clear and light up the eyes and from doing something not for the sake of Heaven we come to doing it for the sake of Heaven. Therefore, it is good for a person to calculate the reward of a mitzva as though a person is standing opposite him and giving him money in his hand for each good thing and for every aspect of the words of Torah. These and others are the strategies to make war with the evil inclination, so that maybe he will be able to drive him out by himself and one who comes to purify himself, G-d will help him.