Pikuakh Nefesh, save a life, is the principle of Jewish law that holds the preservation of human life above nearly every other mitzvah. It is for that reason an extremely important part of the halakha for Jews.
The principle that human life is sacred comes originally from God’s having made us in his image and likeness Gen 1:26–27. God is sacred, therefore his image and likeness are sacred.
God has sought to protect our lives since God told Cain, “ And the LORD said, “What have you done? The voice of your brother’s blood is crying to me from the ground” Gen 4:10.
Rabbi Yeshua elevated Pikuakh Nefesh from earthly life to eternal life, and taught it to his own shlikhim. “I came that they may have life, and have it abundantly” Jn 10:10.
Today the Catholic Church’s whole pro-life outreach is based on this principle. So is the Church’s maxim, § 1789 “One may never do evil so that good may result from it.”