It is written, “To declare … Your faith by night” (Psalms 92:3). Faith is a light.

You can obtain faith through the wisdom of the Torah. Through such scholarship, you can attain some understanding of God, and this is certainly good. But better still is the faith that shines by night. This is pure faith, without any sophistication or proof. This true faith is a light — “Your faith by night.”

A man can be well-versed in the Torah and still have no faith in God.

Such faithless scholars are like those infected with a brain disease called Ra'asan.¹⁸² 77b. This is counted among the 24 skin rashes, and is said to preclude marital relations. It may possibly be identified with syphilis.

footnotes: ¹⁸² Ketubot

It is written, “And my heart saw much wisdom”¹⁸³ (Ecclesiastes 1:16). True wisdom includes faith and is called sight. Sight is RAiYah. On the Other Side, it becomes RaAsan, an affliction of the brain.

footnotes: ¹⁸³ In the Hebrew, the word “much” is omitted.

A scholar without faith is said to be infected with Ra'asan. Rashi comments, “They have a worm in their brains” (Ketubot 77b).

You must keep far away from those tainted with Ra'asan. Their very breath can cause you harm and arouse sexual desires.

It is written, “Adam knew his wife, Eve” (Genesis 4:1). Holy intercourse is called knowledge. The knowledge of those contaminated with Ra'asan is tainted and degraded. “They have a worm in their brains.” Their sexuality is caught up with the forces of the evil husks. Therefore, these faithless scholars are in the category of sexual immorality. Their minds are filled with filth and skepticism. Such immorality is a perversion of sight.

Sight is true wisdom. It is an aspect of eyes. It is written, “I have made a covenant with my eyes” (Job. 31:1). This verse speaks of a true scholar.

But those infected with Ra'asan are immoral and pervert the eyes.

It is written, “And you shall not stray after your heart and after your eyes” (Numbers 15:39). The Talmud explains that “after your heart” is atheism, and “after your eyes” is sexual immorality (Berakhot 12b). One is dependent on the other.

The best protection against such immorality is wisdom with faith.