Musar על קידושין 60:4

For the Creator, blessed be He, who created the evil inclination also created the Torah as its antidote as our sages of blessed memory have stated: "I have created the evil inclination, and I have created the Torah as its antidote" (Kidushin 30b).

So, exactly, is our situation. It is known that the yetzer hara is a man of war, who battles constantly against Israel. Sometimes he defeats us and sometimes we defeat him. And the yetzer says in his heart: "I have no way to defeat Israel. I will see to it to take their shields and weapons with which they fight me (the Torah, which alone defends Israel against the yetzer hara) and it is the weapon with which they fight me" (as Chazal have said [Kiddushin 30b]: "I have created a yetzer hara, and I have created Torah as its antidote," and without it, it is impossible to escape it, as we have written about at length elsewhere.) And so do we see with our own eyes in our time. For this is the way of the yetzer hara, to overcome us by arguments to keep us from learning the holy Torah.