Thousands of baptisms at a Catholic church in Arizona have been invalidated because a priest used the wrong words in performing the ceremony. Father Andres Arango resigned from the St Gregory parish church in Phoenix earlier this month after diocese leaders discovered he had mistakenly used the phrase “we baptize you” instead of “I baptize you” for years. His error means that countless baptisms – an irrevocable requirement for salvation in Catholic theology – will have to be performed again. And some churchgoers could find their marriages are not recognized. “An invalid baptism … invalidates any subsequent sacraments, especially confirmation, marriage, and holy orders,” the diocese of Phoenix said in a webpage intended to answer parishioners’ questions. In announcing the priest’s resignation, the bishop of Phoenix, Thomas Olmsted, urged churchgoers to “join me in praying for Fr Andres and for all of those who are going to be impacted by this unfortunate situation”. The contrite Father Arango, meanwhile, has sought forgiveness in his own message to the faithful. “It saddens me to learn that I have performed invalid baptisms throughout my ministry as a priest by regularly using an incorrect formula,” he wrote. “I deeply regret my error and how this has affected numerous people in your parish and elsewhere,” adding that he would remain a priest and “dedicate my energy and full time ministry to help remedy this and heal those affected”. The fount of knowledge on the matter is the Vatican’s 2020 congregation for the doctrine of the faith, which along with declaring Covid-19 vaccines “morally acceptable” also spelled out the correct words that needed to be used during baptisms. The congregation “affirms that baptisms administered with modified formulas are invalid, including: ‘We baptize you in the name of the Father and of the Son and of the Holy Spirit’,” the Vatican announced. The declaration was deemed necessary following questions over whether such phrasing meant that three separate holy entities were involved in the baptisms, or only one. “The issue with using ‘We’ is that it is not the community that baptizes a person, rather, it is Christ, and Him alone, who presides at all of the sacraments, and so it is Christ Jesus who baptizes,” Olmsted wrote in a message posted to the Diocese of Phoenix website. “I do not believe Fr Andres had any intentions to harm the faithful or deprive them of the grace of baptism and the sacraments. On behalf of our local church, I too am sincerely sorry that this error has resulted in disruption to the sacramental lives of a number of the faithful.” He said the determination was made “after careful study by diocesan officials” and consultation with Catholic leaders in Rome. Arango, who was born in Brazil, became a priest in 1995 and moved to the US in 2001, working at one church in California, then three in the Phoenix area, most recently at St Gregory. The diocese of Phoenix website includes a form to register for a new baptism, and a spokesperson said that several churchgoers have already taken advantage. Any baptisms performed after 17 June last year, when the mistake was discovered, are considered valid, the diocese adds. But anyone who was married after being baptized by Arango is asked to call the diocese urgently. “If your baptism was invalid and you’ve received other sacraments, you may need to repeat some or all of those sacraments after you are validly baptized as well,” the website states.