In 1575 he entered the Order of Augustinian Hermits, was elected superior at one of their houses in Spain, and for some time taught theology.

But wishing to join an order of stricter discipline, he became a Carthusian at Miraflores, where he died prior of the monastery.

[1] Antonio De Molina wrote in Spanish a few ascetical works, especially adapted for priests, which became the most popular books of their kind in Spain, and were translated into various foreign languages.

The most famous of these is a manual for priests and bears the title: Instruccion de Sacerdotes, en que se dá doctrina muy importante para conocer la alteza del sagrado oficio Sacerdotal, y para exercitarle debidamente.

Twenty editions of this work are known to have been published, among them a Latin translation by the Belgian Dominican Nicolás Janssen Boy, which received five editions (Antwerp, 1618, 1644; Cologne, 1626, 1711, and 1712), and an Italian translation (Turin, 1865).