Born on June 5, 1892 his twin brother Julian entered the Passionists. His brother Placidus entered the priesthood and his sister, Sister Mary Noelene entered the Sisters of Charity of Newark, New Jersey. Father Endler took his vows in Pittsburgh on August 3, 1913. He was ordained to the priesthood on January 21, 1923 by William Cardinal O’Connell at St. Gabriel’s Monastery, Brighton, Massachusetts.
Soon after ordination, in 1925 Father Endler began the novena devotion in honor of St. Ann at St. Ann Monastery, Scranton, Pennsylvania. He began the work in a tent that was erected each Monday. There was preaching, confessions, and consolation for those spiritually and physically in need. Many priests, sisters and laity in Scranton sought out Father Endler as a spiritual advisor.
For six years he was Rector of the Passionist Monastery in West Springfield, Massachusetts, and three years as Rector of St. Mary’s Dunkirk, New York. From 1945 to 1953 he was assigned to the Black Catholic apostolate at Mother of Mercy in Washington, North Carolina. Many people throughout the United States made donations to this apostolate. In 1953 he came north to Immaculate Conception Monastery in Jamaica, New York where his health began to fail. He died on October 1, 1957 after extensive suffering from cancer of the neck and throat.