His name was Zacarias Salterain Bizkarra and he was born in Abadiano (Vizcaya, Spain) on November 4, 1887; he did his first studies at the Jesuit college of Durango in Spain; at the age of 15 he entered the Novitiate of the Discalced Carmelites, where on September 12, 1904 he made his profession, taking the name of Zacarias of St. Teresa.

He attended courses in theology and philosophy in the Spanish cities of Bilbao-Begoña, Vitoria and Pamplona, to finish his studies in Rome, where he was ordained a priest on July 14, 1912.

Almost immediately he was sent to the vast missionary field of India and destined for the apostolic seminary of St. Joseph in the city of Puthempally, from there he was then transferred to Alwaye in the Indian state of Kerala, arriving there on November 20, 1912, with the task of teaching philosophy, especially Hindu philosophy, of which he became a talented expert.

In 1913, at the age of 26, he was appointed Prefect of philosophy students; his fast and deserving career among high school students, led him to become at the age of 47, in 1934, spiritual director of the Institute; in 1945 he became vice-rector of the great seminary of Alwaye, which, by now, was attended by more than 700 major clerics of the three Christian rites existing in India, Latin, Malabar and Malankara and of several religious institutes.

Finally in 1955, at the age of 68, he was appointed as Dean of the new distinguished building for philosophers; a position that he held for two years, that is, until his death. His work as a missionary Carmelite took place practically entirely in the teaching and formation of generations of young Indian priests, who despite the distinct forms of Christian worship, typical of the Indian subcontinent to which they belonged, recognized in him the sure guide, the distinguished theologian and philosopher, the spiritual father of their young priesthood.

But Father Zacarias of St. Teresa, did not stand out only for teaching, he was above all an apostolic man of great faith, with a spirit of piety and ardent zeal to achieve the conversion of souls, he was also a valiant director of the seminary.

He was also the author of the "Studies on Hinduism" in 5 volumes, collections which he printed of the lessons of the various subjects he taught. Also in the Seminary, he gave life to the "Sacred Heart Conversion League" Association, dedicated to prayer and penance, and he was a publisher, based in the Seminary, of three periodical publications of his own and of a whole series of pamphlets with popular circulation, concerning apologetics and doctrinal and spiritual formation.

Always requested by all, even by non-Christians, he bestowed without distinction, goodness and help as far as possible. With his evangelical simplicity, generous availability, integration into the Environment and Indian mentality, charity, prayer and poverty, combined with his cultural preparation, he became the figure of the holy missionary, giving moreover honour to the habit of the Discalced Carmelites to which he belonged.

He was a theologian at the First Plenary Council of India, Apostolic Commissioner of the Discalced Carmelite Tertiaries of the Latin rite, effective collaborator of several periodical publications.

In 1957 when he was 70 years old, he was transferred to Vellore, where he was operated on for abdominal cancer, which in recent times had violently shaken his life and his activity; but it was a malign evil and shortly afterwards without complaining, praying and entrusting himself completely to God, he died on May 23, 1957.

His funeral was a solemn one, with the participation of eight bishops, 300 priests and 400 seminarians; he was buried in the cemetery of the seminary; the tomb of Father Zacarias has since become a place of pilgrimage.

The decree on his heroic virtue was promulgated on January 27, 2014.