The Messilat Yesharim makes an interesting analogy between a doctor and the medicine he prescribes and the Yeitzer Hara and its antidote.
If a doctor knows that there is only one medication that can cure his patient, the patient must listen to his doctor. If the patient thinks that he knows better and he takes a different medication, he will certainly hurt himself and might even die.
The same is true of the Yeitzer Hara. Hashem created it in order to test an individual's faith. The Yeitzer is very powerful and is capable of destroying an individual. Hashem created only one antidote to the Yeitzer, and that is the study of Torah. The Talmud tells us that if we are tempted by the Yeitzer, we are to drag it into the Beit Midrash. Only Torah is capable of neutralizing it. If someone believes that he can choose another means of weakening the Yeitzer by anything other than Torah, he will fail. The New Morality or Liberalism will not succeed in this battle. The only cure is designating definite time periods for the study of Torah. Good advice from the Messilat Yesharim.