Häring was born at Böttingen in Germany to a peasant family. At the age of 12, he entered the seminary. Later, he took vows as a Redemptorist, was ordained a priest, and sent as a missionary to Brazil. He studied moral theology in obedience to his superiors.
During World War II, he was conscripted by the German army and served as a medic. Although forbidden from performing priestly functions by the Nazi authorities, he brought the sacraments to Catholic soldiers.
In 1954, he came to fame as a moral theologian with his three volumed, The Law of Christ. The work received ecclesiastical approval but was written in a style different from the Manual Tradition. It was translated into more than 12 languages.
Häring taught at various universities including the University of San Francisco, Fordham, Yale, Brown, Temple, and the Kennedy Institute for Bioethics at Georgetown.
A prolific writer, Häring produced about 80 books and 1,000 articles.