An evangelical pastor who has been jailed in Iran for his Christian activities said Monday he was told by a court to remain behind bars because he "did not change," according to BosNewsLife. Pastor Behnam Irani made it clear he remained faithful to Christ, despite court pressure to return to Islam. "I've the joy of the Holy Spirit," Irani said. "I'm very thankful for Christian activists who are fighting alongside with us." Irani, 43, began a one-year prison term in 2011 but was later told he would also have to serve a five-year previously suspended sentence for "crimes against national security." There has also been concern he may face execution after a court advised such a sentence for alleged "apostasy," or abandoning Islam. Christians have linked the sentence to Irani's activities as pastor of a 300-strong house church congregation of the evangelical Church of Iran movement. Irani is held at the Ghezel Hesar Prison in Karaj city, one of the toughest jails in the country. He confirmed that the mistreatment and poor hygiene in the prison left him in poor health, including reported intestinal problems and rheumatism, but said he is "is fighting." Despite the difficulties, he told BosNewsLife he was "doing fine" as his Christian faith keeps him strong.