Alphonsus was ordianed a diocesan priest in 1726 where he focused much of his vocation training catechists to work in the slums and with the poor. He was later ordered by his doctor to retreat to the countryside to rest and focus on inprove his health. There, Alphonsus continued his quest for catechizing as he worked closely with the natives in the mountains.
Upon his return, Alphonsus later met a religious sister whom had had visions of him forming a religious order for men. With much discernment and direction from theologians, he founded the Congregation of the Most Holy Redeemer on November 19, 1732.In 1762 Alphonsus was appointed and consecrated as a bishop. He focused his work with renewing the seminary and strengthening the spirituality of the clergy and lay members in his diocese. Throughout his time as bishop Alphonsus was still seen working closely with people in need as he served the poor and even opened his residence up to them.
Alphonsus resigned as bishop in 1775 and later returned to his native village as his health began to deteriorate.
On August 1, 1787, Alphonsus died. He was beatified September 15, 1816 and canonized May 26, 1839. In 1871 Pius IX declared St. Alphonsus Liguori a doctor of the Church and in 1950, Pius XII declared him the patron of moralists and confessors.