Musar su II Re 20:12

But if he toils in the Torah, when he sees its ways, commandments, and warnings, behold, on its own, eventually a renewal will awaken within him which will bring him to the good path. This is what our sages of blessed memory stated: "would that it were that they abandoned Me but kept My Torah, for the light within it would bring them back to the good" (Eicha Raba 2).

The second detrimental factor, laughter and levity, is very severe. For one who is immersed in these is like one immersed in the great sea, from which it is extremely difficult to escape. For behold, laughter destroys a man's heart until reason and knowledge no longer rule in him. He becomes like a drunkard or a madman whereby it is impossible to give counsel or guide them for they are incapable of accepting any direction.