One changed word may not seem like much.
But one Catholic priest's use of the word 'we' instead of 'I' during both English and Spanish language baptism ceremonies during his two decades in the ministry has left thousands of baptisms invalid in multiple parishes in two countries.
Father Andres Arango stood down from his role as a pastor with the Diocese of Phoenix in the United States earlier this month after it was revealed he had used this formula during the sacrament: "We baptise you in the name of the Father, and of the Son and of the Holy Spirit".
Instead, he should have said the same words starting with "I baptise you … "
Fr Andres had previously worked as a priest in Brazil, in San Diego and within Arizona and he said he was saddened to learn he had performed "invalid baptisms throughout my ministry as a priest by regularly using an incorrect formula".
It does not stop there, with the Diocese of Phoenix saying invalid baptisms would also invalidate subsequent confirmations, marriages and holy orders.
Vatican says no priest has authority to change wording
After learning of the mistake, Bishop of Phoenix Thomas J Olmstead said he had consulted with diocesan officials and the Vatican's Congregation for the Doctrine of the Faith, and been informed that the baptisms were invalid.
"The issue with using "we" is that it is not the community that baptises a person, rather, it is Christ, and Him alone, who presides at all of the sacraments, and so it is Christ Jesus who baptises," Bishop Olmstead said in a statement.
"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."
In a statement from the Vatican in 2020, Archbishop Giacomo Morandi said it appeared there had been instances where the words were changed to "emphasise the communitarian significance of baptism", to allow those present to participate and avoid the concentration of power with the priest to the detriment of the family.
But he said this was a misunderstanding of the nature of the ministry.
"The Second Vatican Council has likewise established that no-one, 'even if he be a priest, may add, remove, or change anything in the liturgy on his own authority,'" he said.
"Modifying on one's own initiative the form of the celebration of a sacrament does not constitute simply a liturgical abuse, like the transgression of a positive norm, but a vulnus [wound] inflicted upon the ecclesial communion and the identifiability of Christ's action, and in the most grave cases, rendering invalid the sacrament itself, because the nature of the ministerial action requires the transmission with fidelity of that which has been received."
The Diocese of Phoenix said it was working with those affected and there would be some flow-on effects, including a reminder that only those who had been validly baptised could receive communion.
"As the entry point to other sacraments, an invalid baptism therefore invalidates any subsequent sacraments, especially confirmation, marriage and holy orders (ordination to the priesthood or diaconate)", the Diocese of Phoenix wrote on its website.
While Fr Andres has resigned from his position as pastor, the Diocese of Phoenix said he was not disqualified from vocation and ministry and remained "a priest in good standing".
"With the help of the Holy Spirit and in communion with the Diocese of Phoenix, I will dedicate my energy and full-time ministry to help remedy this and heal those affected," he said.
"I sincerely apologise for any inconvenience my actions have caused and genuinely ask for your prayers, forgiveness, and understanding."