The attack was captured on video during the 11 a.m. Mass at Cathedral Basilica of Saints Peter & Paul while the service was streaming online.
Video shows Sarah Contrucci, 40, a longtime lector, leaving the altar as a woman punches her twice. It's still unclear what sparked the attack.
Contrucci did not require medical attention.
"I hope that she learns to love the Lord and maybe even come back to Mass someday and is respectful," Contrucci said.
Contrucci said the woman muttered something to her before she was hit.
"Something about respecting God and I couldn't make out much else," said Contrucci. "I was worried she was going to attempt to make a scene of some sort to disrupt the Mass, so I was thinking I could do everything to keep the situation calm and respectful...I just wanted to get back to my pew and allow the Mass to resume."
Mass was able to resume and the suspect walked out of the church.
Father Gill says staff immediately called 911 and they have security measures in place but are reviewing them in the wake of what happened.
The Basilica is open everyday for people to come and go and Gill says everyone is welcome but he wants everyone to feel safe.
"It's obvious we need more of a presence of the police and others to ensure a higher level of security," Gill said. "It's a very unsafe time in many ways, so I don't want to fault anyone in the congregation or in the sanctuary up front for their response. I want to assure everyone that when things like this happen we do have something in place and the very first thing we do is contact the police we call 911 and we have people internally to assist. As everyone knows, as many protocols and plans you have in place random acts like this are often very hard to prevent from taking place."
Sources tell Action News that a suspect was taken into custody. No charges have been filed at this time.
Read Philadelphia Archbishop Perez's full statement below:
"During the 11:00 a.m. Mass at Cathedral Basilica of Saints Peter & Paul, which was broadcast live via my Facebook page and the Archdiocesan Vimeo Channel, a senseless act of aggression took place. One of the lectors was punched by someone in the congregation as she left the altar.
Such behavior is unacceptable at all times, especially within the confines of a church building and during the celebration of the Holy Mass. I was saddened to learn of this incident and regret that it took place. The lector who was assaulted received immediate attention and assistance from Cathedral staff members off camera. She did not require medical attention and is doing well based on the reports I have received. The Archdiocese of Philadelphia is working in conjunction with police regarding the matter and will cooperate with them fully. Please be assured that there are safety and security plans in place for the Cathedral Basilica of Saints Peter and Paul. We welcome all visitors and work to provide for their safety. Violence has no place in our world and every life is a precious gift from God. Please join me in praying for everyone involved in today's incident and for respect for our fellow brothers and sisters."