In general, a human life is of paramount value from the perspective of the Torah, and one is not required to sacrifice his life in order to fulfill its commandments. But in the context of specific commandments, or under specific circumstances, the sacrifice of one’s life constitutes the sanctification of God’s name in the world.

The commandments were given to Israel only so they could live by them, as it is stated: “Which a person shall perform and live by them” (Leviticus 18:5). The verse teaches: “And live by them,” and not that one should die by observing them. There is nothing that stands in the face of a life-threatening situation except for idol worship, forbidden sexual relations, and bloodshed [where one must refrain from violating these prohibitions even it costs him his life]. In what case is that said? It is said when it is not a time of persecution by the government. But in a time of persecution a person must sacrifice his life even for the observance of the least significant commandment. (Tosefta Shabbat 15:17)