The violent onslaught of the radical Islamist group Boko Haram has forced the Diocese of Maiduguri, which has suffered most from the militants, to effectively shrink to half its size according to its bishop.

Since Boko Haram began its offensive nearly five years ago, half of the parishes in the Diocese of Maiduguri have been deserted, according to Bishop Oliver Doeme. Ongoing violence has also displaced nearly half the local priests.

"We are thoroughly devastated by the Boko Haram attacks…as a Church, families, and individuals," Bishop Doeme wrote in a Nov. 6 pastoral letter, which was obtained by Aid to the Church in Need. "We are wounded, traumatized, and devastated."

The same day, Bishop Doeme told Channels TV that of the 46 priests working in his diocese, 20 have been displaced by Boko Haram; some are being sheltered in the neighboring Yola diocese. Twenty of Maiduguri's 40 parishes have been deserted, with many of them looted, taken over, or burned down by Boko Haram.

The Diocese of Maiduguri includes most of Borno State in northeastern Nigeria. The diocese also extends into the nearby states of Adamawa and Yobe. All three states have been living in an official state of emergency since May 2013.

Bishop Doeme wrote that there is no answer to the question of the evil the region is experiencing through Boko Haram.

"But, for sure, the ultimate result of our pains and anguish is for God's name to be glorified and for our own purification and edification," he wrote.  

The bishop published his pastoral letter one day before a suicide bomber with apparent ties to Boko Haram detonated near a bank in Azare, which is located in Bauchi state, which borders Yobe. The blast killed at least ten people.

On Nov. 10, another suicide bomber attacked a school assembly in the nearby town of Potiskum. The blast killed at least 46 students, according to the BBC. Police have suggested Boko Haram was behind the attack, which lead to a shutdown of all public schools in the area.

Boko Haram has also advanced its control in recent days, having captured both Mubi and Maiha in Adamawa; its control now extends to within 100 miles of Yola.

In his pastoral letter, Bishop Doeme wrote that prayer is the answer to the ongoing violence. He urged the faithful to cling in prayer to Jesus, the Virgin Mary, and Nigeria's countless modern martyrs.

"We don't have physical weapons such (as) armored tanks, APC, Jet fighters, rocket propellers, rocket launchers, AK47 among others. The enemies trust in these arms, but we in the Lord," he reflected.

"Do not grow weak in prayer. This can be the devil's strategy to cut the line of communication between you and your Lord."

Boko Haram's attacks have killed thousands since 2009; including at least 4,000 in 2014 alone, according to Human Rights Watch. The U.N. estimates that the attacks have led to more than 470,000 internally displaced persons, and some 57,000 refugees.

In the face of all this, Bishop Doeme urged his people to "never get discouraged. Our faith should make us see beyond the immediate experience and look at the future – that is, after this temporal life with its pains and suffering, we shall share in the eternal glory of our Lord. And so we need to have unshakable faith in God despite what we are experiencing. I always tell you my people that there are two precious gifts of the Lord that on no account should we allow anybody to separate us from them. And these are our faith and our souls."

Bishop Doeme reassured the faithful that "what we are experiencing does not in any way imply that God is loving us less," and that in Mary "we have a mother who never fails."

"A big lesson we are learning from this crisis is that we need to draw closer to God," he stated. He also urged the importance of forgiveness, saying it is "the only thing we can give to the terrorists and their sponsors. Forgiveness in this instance is very difficult. But we must forgive, since our Lord Jesus forgave his executioners."

Bishop Doeme encouraged his people to rejoice, "because God the Father is with us; God the Son is with us; God the Holy Spirit is with us. Be consoled because our Mother Mary is with us. The Archangels and our patron angels are with us. The countless saints in heaven are with us."

"The modern martyrs, our brothers and sisters killed because of the persecution, have joined the triumphant army in heaven and are interceding for us daily."

"Be consoled, for I, as your servant (bishop) am with you in spirit wherever you are, whether in the forests or mountains, or caves or bushes, towns or villages, I am there with you sharing in your pains, troubles, anxieties and anguish."