QUINCY -- Msgr. Stephen J. Rossetti had his first encounter with demons when he was a seminarian.

As he lay in bed, Msgr. Rossetti, founder of the St. Michael Center for Spiritual Renewal and author of the book "Diary of an American Exorcist," felt himself being pinned down by an unseen force.

He "lunged out of bed" to grab his rosary, and the moment he grabbed it, the demonic force disappeared. Since then, he sleeps with his rosary every night. The only time he is without it is when he showers.

"Demons are incredibly powerful and incredibly fast," he said. "They move at the speed of thought. The weakest demon in the world could beat you up a lot."

Compared to the Virgin Mary, however, demons are "dust."

Msgr. Rossetti was one of the keynote speakers at the third annual Boston Marian Conference, held at the Boston Marriott in Quincy on Oct. 28 and 29. The Pilot attended the conference on Oct. 28.

Other speakers at the conference included Father Michael Lightner, a would-be NFL player who decided to trade football for the priesthood after visiting Medjugorje; Father John Anthony Boughton, a Protestant who became a Franciscan after visiting Medjugorje; Archdiocese of Boston Senior Development Officer Artie Boyle, whose terminal cancer disappeared after visiting Medjugorje; and Rev. Dr. Gus Succop III, a Presbyterian pastor who embarked on a pilgrimage to Medjugorje, which deepened his relationship with Mary.

Over 600 people joined the Hingham-based 5 Stones of Mary Foundation for a "grace-filled weekend" of prayer, evangelization, and talks about the influence of Mary on Catholicism and the world.

"Our Lady chose Boston," said Marian Conference Executive Director Colleen Willard. "She's only chosen me to be an instrument to help organize, and it's a gift to serve Our Lady, Our Queen, Our Mother, and her son Jesus."

The conference and the foundation are centered around the 1981 apparition of Mary to six children in the village of Medjugorje, then part of Communist Yugoslavia.

Ivan Dragicevic, one of the original Medjugorje visionaries, told the conference that Mary comes to humanity as "the greatest mother and teacher."

"All of us gathered here today, we carry with us crosses, illnesses, difficulties," he said with the help of an interpreter. "We've brought them all here to Our Mother so that she can pray and intercede before her son, because she is the best intercessor for all of us."

He recalled his experience witnessing Mary at such a young age.

"Just to look upon Our Lady," he said, "to be with her and before her, means to be in awe of her beauty."

He and the other children asked Mary, "Why are you so beautiful?"

"My dear children," she replied to them, "I am beautiful because I love. If you love also, then you will be beautiful."

Mary told the children that humanity's greatest crisis is one of faith, and that humanity, "the lungs of the church," must turn back to God. She encouraged prayer for universal peace, fasting, penance, forgiveness, attending Mass, and reading Scripture as a family. If humanity's relationship with God falters, she said, then humanity is at risk of destroying itself.

Dragicevic said that Mary is more concerned about the world than ever, due to the present "war in her homeland."

"Our Lady is trying to lead us out of the spiritual coma the world is in," he said.

In his talk, Msgr. Rossetti warned Catholics not to scoff at the existence of demons, but not to fear them either. As an exorcist, he does not fear demons, but demons fear Mary more than anyone else.

"Of course, you get roughed up a bit" on the job, he said, "but it's minor. The only things that happen to you are what God allows."

He also cleared up Hollywood misconceptions about exorcism. He explained that people who are "fully possessed" by demons should see a priest, but people with a "demonic issue" that is not possession should pray prayers of deliverance. Such prayers are available on his free Catholic Exorcism phone app.

"Exorcism is a prayer," he said.

Msgr. Rossetti, who has accounts on Facebook, X (formerly Twitter), Instagram, and TikTok, said that social media is a key tool for evangelization in the 21st century.

"That's where they're at today," he said. "They're on social media, they're on their phones."

He said his TikTok presence is especially important due to "WitchTok," a subculture of TikTok users who post videos of themselves performing witchcraft.

"My bottle of holy water isn't big enough," he said.

To gasps of shock from his audience, he described "demonic" behaviors among young people, such as satanic tattoos and occult practices, such as the use of Ouija boards. The solution, he said, is for priests to show their flocks that they do not fear demons.

"That's what we do," he said. "We cast out demons, and we preach the good news. If you haven't riled Satan in your life, are you preaching the good news?"

Bishop Mark O'Connell celebrated Mass at the conference. Wearing white vestments in honor of Mary, he said that Cardinal Seán P. O'Malley was "thrilled" by such a gathering taking place in his archdiocese. Cardinal O'Malley could not attend in person because he was in Rome participating in the Synod on Synodality.

In his homily, Bishop O'Connell said that Mary's love of God may seem unattainable, but it is not. Rather, it is an example for all Christians to follow.

"She changed his diapers," he said. "She held the boy Jesus's hand. She had such incredible access. Literally within her womb was the Son of God."

He said that Catholics must imitate Mary by comforting the sick, the poor, the homeless, refugees, and widows.

"Upon the Cross, God gave her our heart to love," he said. "Now Mary loves us, comforts us with that beautiful heart that, as the prophet said, was pierced. How it was pierced! But it loved anyway."

Everyone at the conference, he said, was afflicted with something that pierced each of their hearts. He told them to offer their pierced hearts to Mary.

"Mary understands," he said. "Mary loves and shows you how to love."