A Christian woman who was captured for five weeks by Boko Haram militants in northern Nigeria has told of her joy after being adopted by a foster family following a period in an internally displaced people's (IDP) camp.

Mercy James, 23, from Gyoza in Nigeria's north-eastern Borno State, was seized along with four other women in June 2014 when militants took over the town and declared it an Islamic caliphate. She was separated from her father and she presumes he was killed for refusing to renounce his Christian faith.

"My first day was like hell," she told Open Doors. "I cried all day and all night. I prayed like never before and asked God to give me courage."

Open Doors met Mercy last year, when she had been left to live in an internally displaced people's (IDP) camp. "She was destitute, injured and deeply traumatised," said Open Doors, which sought to help her with counselling, medical expenses, income generation and encouragement through letters from the charity's supporters.

Now, Mercy no longer lives in the IDP camp but has instead been taken in by a foster family. Open Doors said that "within the context of distrust and isolation often experienced by former Boko Haram captives, this is an extraordinarily fortunate situation".

A serious injury that Mercy had sustained to her leg during an aerial bombardment has healed.

With the support of Open Doors, Mercy has started a successful tailoring business. "The transformation has been so radical, that was hard to recognise her," wrote an Open Doors worker.

"The sewing machine and monetary support I received helped me a lot," Mercy told Open Doors. "I started up my own business and now have a shop. A lot of people bring their clothes for me to sew; I can now cover my needs and those of my [foster] family."

Open Doors, together with international visitors, recently went to see Mercy in order to pray with her, encourage her, and deliver letters of support from the charity's supporters.

"I am so happy because I know that I am not alone and that other believers out there are praying for me," Mercy said.

One letter-writer included a bracelet. "I was deeply touched by the bracelet I received," she told Open Doors. "Though it's just a bracelet, it has a deeper meaning. All the colours on it speak about Psalm 23."

She added: "I am overwhelmed and my heart is filled with joy seeing Open Doors here again. Words cannot express the joy and peace I have. All I can say is, may God continue to bless your charity and all those who are out there praying for us in northern Nigeria.

"For other believers who are being persecuted because of Christ, I have this to say: though you walk through the valley of the shadow of death, fear no evil for God is with you. If God delivered me, He will do the same for you."