Spiritual healing

There is a story about a certain patient whose doctor despaired of healing him. The sick man's condition continued to worsen, until he could no longer speak. It happened that the Baal Shem Tov came to the place where the patient lived, and asked to visit him. Upon arriving, the Baal Shem Tov ordered some meat stew to be made, and gave it to the patient, who immediately began to speak again. After this, the Baal Shem Tov healed him until he was completely healthy again. 

The doctor was shocked to see the patient healthy again, and asked the Baal Shem Tov how he healed him. "I know for certain," said the doctor, "that his vocal cords were damaged, and there was no way that they could be cured!" 

Replied the Baal Shem Tov, "You 'diagnosed' the patient physically, while I 'diagnosed' him spiritually.
A human being is composed of 248 primary organs and 365 primary veins, corresponding to the 248 obligations and 365 prohibitions of the Torah. When a person blemishes some commandment, the corresponding organ or vein becomes damaged, and if he violates many prohibitions, many veins are damaged, preventing the blood from flowing in them, and this puts him in danger. I spoke with the patient's soul that it should accept to return to the proper path, and his soul agreed. Because of this, all the organs and veins were repaired, and I was able to heal him afterwards." 

~ Sippurei Chasidim, #199 Parshas Mishpatim

This is all well for a Jew, who was given 613 commandments at Mount Sinai, but what of a Gentile? Is it possible for him to effect a spiritual cure? It is evidently possible, as there are also stories of tzaddikim who healed Gentiles. However, the mechanism must obviously have been somewhat different, since Gentiles do not have the 613 commandments of Moses, but only the 7 commandments of Noah:

1. To not worship false gods.
2. To not curse the True G‑d.
3. Not to steal.
4. Not to have illicit relations.
5. Not to murder.
6. Not to be cruel to animals.
7. To set up courts of justice.

It is noted that these commandments contain many sub-details, including implied obligations, such as to protect people's lives and so on. It appears to me that this encompassing, general aspect of the Noahide laws stems from the nature and origin of the Gentile soul, which differ from those of a Jewish soul.

In detail, although all souls derive their life-force from the spiritual Order of Devolution (Seder Histalshelus), a Gentile soul emerges from a higher, more powerful and abstract level within this chain of devolution than a Jewish soul (see the maamar Reishis Goyim Amalek, "An End to Evil"). Hence, while a Gentile can derive life-force from the general, encompassing Noahide laws, a Jewish soul can only (sustainably) derive life-force through the specific commandments listed in in the Torah. The commandments of the Torah are so circumscribed and specific because they emerge only after passing through more limiting tzimtzumim than the Noahide laws.

The greater power of a Gentile's soul is reflected in several traditional Jewish sources.

For example, the Rebbe tells in detail how Esau was originally to receive the birthright instead of Jacob, because his "wild," unlimited soul had the potential to transform the physical world directly, for holiness, and this is why Isaac favored Esau as his successor (Likkutei Sichot, vol. 20, pp. 108–115). Since Esau is identified as the representative of the Gentile world, this is a statement about Gentiles in general.

For a further example, the Talmud (Avodah Zara 52b) mentions that even after destroying an idol, a Jew may not derive any benefit from the remains (such as using the gold, or cooking with the wood from a destroyed idol). However, if a Gentile idolater were to permanently nullify the idol (e.g. by breaking off its nose), the material in the idol and any of its accessories becomes permitted to a Jew. This is a special power that Jewish law does not grant to a Jew, but specifically only to Gentiles.

Returning to the topic of spiritual healing, it appears that a Gentile may similarly suffer illness due to a blemish in in the seven Noahide commandments. By renewing his resolve to follow the seven laws, which eventually give life-force to the same organs and veins as the 613 Jewish commandments, the blemish can be repaired, and the illness cured. Alternately, since one who enables fulfillment of a commandment also receives credit for it, a Gentile could help a Jew fulfill one of the 613 commandments, and hence receive a blessing in the corresponding organ or vein, as in the story above.

Whichever strategy is followed, it is certain that the Talmud's promise will be fulfilled, and that "one who comes to be purified is aided" from on High (Yoma 38b).