Why does God allow suffering, according to Judaism?

The question is legitimate

Jewish tradition does not forbid the question. Abraham argued with God over Sodom: “Shall not the Judge of all the earth deal justly?” (Genesis 18:25). Job’s friends offered tidy explanations and God rejected them. The Talmud reports that Moses asked to understand why there is “a righteous person who suffers and a wicked person who prospers”.

Partial answers

Several ideas appear in the sources. Free will: if God prevented every evil act, human choice would be meaningless. Growth and testing: hardship can draw out strengths that comfort never would. The wider picture: reward and justice are not limited to this world. Isaiah describes God as the one who “makes peace and creates evil” (Isaiah 45:7) – nothing is outside God’s rule, even what we cannot understand.

Humility

Pirkei Avot says plainly: “It is not in our hands – neither the tranquillity of the wicked nor the suffering of the righteous.” Jewish tradition is wary of explaining another person’s pain; the friends of Job were faulted for doing so.

What we do

The practical answer is a response, not a theory: to comfort mourners, visit the sick, give charity and work against injustice. On hearing bad news a Jew says “Blessed is the true Judge” – an expression of trust, not of understanding.