Bishop Schlert was born July 24, 1961, the son of Alfred and Marylou Schlert in Easton, Pennsylvania, where he attended St. Jane Frances de Chantal Elementary School, and Notre Dame High School. His ecclesiastical studies were undertaken at St. Charles Borromeo Seminary, Philadelphia, the Pontifical Roman Seminary, and St. John Lateran University, Rome. He was ordained a priest on September 19, 1987, at the Cathedral of Saint Catharine of Siena on September 19, 1987 by Thomas J. Welsh, Bishop of Allentown. He served as an assistant at St. Francis of Assisi Church in Allentown, as a professor at Notre Dame High School in Easton, and as a chaplain at Lehigh University in Bethlehem. He then completed graduate studies at the Lateran, where he received a Licentiate in Canon Law in 1992. In 1997, he was named Vice Chancellor and Secretary to Bishop Welsh. In 1998, Bishop Edward P. Cullen appointed Father Schlert Vicar General, overseeing the coordination of all administrative offices of the Diocese. Pope John Paul II named him Chaplain to His Holiness with the title of Monsignor in 1999. Pope Benedict named him a Prelate of Honor, the second highest rank of Monsignor, in 2005. In addition to his administrative responsibilities, in 2008 he became pastor of St. Theresa of the Child Jesus Church in Hellertown.
Bishop of Allentown
appointed Schlert bishop for the Diocese of Allentown on June 27, 2017. His consecration and installation took place on August 31, 2017.
Sex Abuse Investigation
In a grand jury report released by Pennsylvania Attorney General Josh Shapiro on August 14, 2018 "Excerpts from the report depict Schlert as someone quick to confront priests who were the subject of abuse complaints. He, along with a fellow monsignor, helped facilitate several resignations and retirements from priests suspected of sexually abusing children. His inquiry with one accused priest triggered the process of that priest being laicized, or defrocked." Monsignor William Jones was accused of sexually abusing a boy. Two days after the victim reported the abuse, Schlert and fellow Monsignor John B. McCann intervened. They confronted Jones who "offered his resignation and was advised he could not exercise any public ministry in the diocese or elsewhere." In 2007, the diocese received a report of a boy who was allegedly given alcohol and inappropriately touched by Father Joseph Galko. Msgr. Gerald Gobitas and Schlert confronted Galko, who admitted the allegation. "The diocese laicized Galko and he was eventually dismissed from the priesthood,". In August 2018, Bishop Schlert issued a public apology "for the past sins and crimes committed by some members of the clergy." Attorney General Shapiro has strongly criticized Schlert for what he perceives as the Bishop's actions when he was a Monsignor. However, some of the public feel that these attacks are in the least unwarranted and unfair.