A Nigerian bishop says that he has seen Christ in a vision and now knows that the rosary is the key to ridding the country of the Islamist terrorist organization Boko Haram.

Bishop Oliver Dashe Doeme says he is being driven by a God-given mandate to lead others in praying the rosary until the extremist group disappears.

"Towards the end of last year I was in my chapel before the Blessed Sacrament… praying the rosary, and then suddenly the Lord appeared," Bishop Dashe told CNA April 18.

In the vision, the prelate said, Jesus didn't say anything at first, but extended a sword toward him, and he in turn reached out for it.

"As soon as I received the sword, it turned into a rosary," the bishop said, adding that Jesus then told him three times: "Boko Haram is gone."

"I didn't need any prophet to give me the explanation," he said. "It was clear that with the rosary we would be able to expel Boko Haram."

The bishop said he didn't want to tell anyone, but "felt that the Holy Spirit was pushing him to do so."

He started with the priests of his diocese, and then told participants in the April 17-19 #WeAreN2015 congress in Madrid, Spain. The event is being sponsored by the Spanish Catholic sister groups hazteoir.org and CitizenGo to gather ideas on how to preserve the Christian presence in nations where they are most persecuted.

Bishop Dashe leads the Diocese of Maiduguri, in northeastern Nigeria's Borno State. In 2009, there were around 125,000 Catholics under his guidance. After a surge in violence from the Islamist extremist group called Boko Haram, today "there are only 50 to 60 thousand left," he said.

Most of those who fled sought safer areas in other parts of Nigeria, he said. Some of the same families are now returning home as armed forces from Nigeria, Chad and Cameroon liberate their homes.

In 2014, Boko Haram became known worldwide when members kidnapped nearly 300 girls from a school in Borno State. On March 7, 2015, five suicide bombers killed 54 and wounded nearly three times as many in the capital city of Maidaguri, where the bishop lives and works.

The group has killed 1,000 people across Nigeria in the first three months of 2015, according to Human Rights Watch, which reports that more than 6,000 have died in Boko Haram-led violence since 2009.

Just last month, the group pledged its allegiance to ISIS – also known as the Islamic State – which launched a bloody campaign in Iraq and Syria last summer.

Meanwhile, Bishop Dashe has just completed a "consolation tour" to communities in his diocese, promoting forgiveness and continued faith. He believes he was asked by Jesus to spread devotion to the rosary in order to aid them as they do so.

"Maybe that's why he did it," said the bishop, referring to Jesus in his vision.

Bishop Dashe said he has a strong devotion to Christ's mother, and that "I never joke with 'Mamma Mary.' I know she is here with us."

And he is not the only Nigerian bishop putting the future of the country in the hands of Mary. The nation's bishops' conference has consecrated the country to her twice in recent years.

Bishop Dashe believes that one day his diocese will completely recover and grow thanks to her intercession.

"These terrorists… think that by burning our churches, burning our structures, they will destroy Christanity. Never," Bishop Dashe told several hundred people from the dais of the #WeAreN2015 congress.

"It may take a few months or a few years … but 'Boko Haram is gone.'"

He later told CNA that "prayer, particularly the prayer of the rosary, is (what) will deliver us from the claws of this demon, the demon of terrorism. And of course, it is working."