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.