Leah Sharibu has been held captive by the Boko Haram faction known as the Islamic State West Africa Province (ISWAP) since February 2018.
The 15-year old was among 110 girls abducted in from their school in Dapchi, Yobe state.
While all of the surviving girls were freed, Leah wasn't as she refused to renounce her Christian faith and convert to Islam.
The World Evangelical Alliance (WEA), the Association of Evangelicals in Africa (AEA) and the Nigeria Evangelical Fellowship (NEF) have urged the international community to join them in praying for Leah.
Speaking on behalf of the organisations, Bishop Efraim Tendero, Secretary General of the WEA, said in a statement: "Leah is a 15-year old girl who could have saved her life by converting to Islam, but chose not to renounce her faith in Jesus Christ.
"Instead - and at the expense of her freedom - she remained strong in her faith and her relationship with Jesus, which serves as an inspiration and role model for all of us. Please join us in prayer for Leah and Alice that they will gain strength, comfort and assurance that they are in the good hands of our God."
Alice Ngaddahis, a mother of two, is also being held by ISWAP.
The terrorists recently vowed to make the pair a "slave for life" and said that "it is now lawful for us to do whatever we want with them".
Bishop Efraim added that the Nigerian government need to make more of an effort to make sure Leah and other hostages are released.
"Together with the NEF and AEA, the WEA also calls on the government of Nigeria to invest more efforts and resources to free Leah Sharibu, Alice Ngaddah and other hostages, and to put an end to the violence of Boko Haram," he said.
"We also call on the international community to support the Nigerian government in addressing the persecution of Christians and others that has already been going on for many years."
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