Cardiel was born in La Guardia, Rioja, on 13 March 1704. He studied in the Jesuit schools of Victoria, together with two of his brothers who entered the order. Of these three, two later went on Jesuit missions in the Indias. Pedro Antonio went to the missions in Quito and for a third of a century worked without rest in that area. José, who was the youngest of the brothers, entered the order on 8 April 1720. He made his novitiate in Villagarcía and studied philosophical and theological sciences at Medina del Campo. In 1729, when Cardiel arrived in Buenos Aires he was already a priest, and shortly thereafter he was working in the Guaranian Indian settlement around Paraguay, first as deputy parson in 1731, and from 1735 as parson. After a short period at the Colegio de las Corrientes, in 1743 he was designated to cooperate in the foundation of the Indian settlements of the Mocobies of San Francisco Javier, Abipones, Charrúas, and Guaraníes. Cardiel learned the local languages, especially guaraní, which he highly esteemed, and learned to perfection. Between August 1745 and August 1746, Cardiel explored the Patagonian coasts, and immediately afterwards went into the interior of this region, arriving at the Sierra del Volcán, and later at the Claromecó river. In 1747, he returned to the Abipones, and this time he founded, together with other brothers of the order, the Abipone settlement of San Jerónimo, which later would become the city of Reconquista. He stayed there for two years through the arduous and difficult beginnings of this settlement.