Graduate, St. Leonard Seminary, Dayton, Ohio. Graduate, Assumption-St. John's Seminary, San Antonio.
He is the second and current Bishop of San Bernardino. He was ordained to the priesthood, for the Archdiocese of San Antonio, on 20 December 1975. On 28 January 1992, Barnes was appointed Auxiliary Bishop of San Bernardino, California and Titular Bishop of Mons Faliscus by Pope John Paul II. He received his episcopal consecration on 18 March 1992 from Bishop Philip Straling, with Archbishop Patrick Flores and Bishop Curtis Guillory, SVD, serving as co-consecrators.
He selected as his episcopal motto: "Amar Es Entregarse", meaning, "Love is the total giving of oneself."
Barnes was later named the second Bishop of San Bernardino on 28 December 1995. The focus of his episcopal ministry has been the diocesan Pastoral Planning Process. Within the United States Conference of Catholic Bishops, Barnes currently chairs the Committee on Migration and Refugee Services.
In that post, he has described the "current immigration system" as responsible for "family separation, suffering, and even death" and "is morally unacceptable and must be reformed". He formerly chaired the Committee on Hispanic Affairs from 1996 to 1999. Under the guidance and support of Bishop Gerald Barnes, the Diocese of San Bernardino is privileged to have three high schools, twenty-three elementary schools and three pre-schools to serve the families in the Diocese.
In 2001, Bishop Barnes, through the assistance of the Diocesan Office of Catholic inaugurated the Annual Bishops'Golf Classic. During Bishop Barnes' tenure, 4 of the Diocese's elementary schools have closed. These include schools in Barstow, Banning, Apple Valley and San Bernardino.
Currently, the High Desert portion of the Diocese has no Catholic schools. On 11 March 2014, Barnes, citing economic benefits and good citizenship, encouraged his flock to sign up for insurance under Obamacare.