Ali Shahvari grew up in a traditional and religious Muslim family in Iran. He was devoted to his country to the extent that he twice volunteered to fight on the front lines in the devastating Iran-Iraq War. But after one of his brothers was killed and another wounded in the 1980-88 conflict, he turned to drugs.

Two decades later he found salvation on satellite television. After initially questioning the messages of Jesus Christ broadcast in Persian from abroad, Shahvari eventually converted to evangelical Christianity under a new name, Iman (Faith).

But his path resulted in multiple arrests, a year in detention, and charges of blasphemy, acting against national security, and engaging in evangelical activity with the aim of attracting others to "deviant thoughts."

That is because it is illegal for Muslims to convert in Iran, where unrecognized religious minorities are barred from assembling.

Article 18, a London-based nonprofit organization that promotes religious freedom in Iran and advocates on behalf of its religious minorities, has documented the experiences of many who, like Shahvari, were forced to flee abroad to pursue their religious beliefs or who remain and are persecuted in Iran.

The organization's latest annual report, produced jointly with other religious advocacy groups, reports more than 120 incidents of arrest, detention, or imprisonment of Christian converts, Iran's largest Christian community.

The joint report says that one of the most striking trends in 2021 was the increased involvement of Iran's powerful Islamic Revolutionary Guards Corps (IRGC) in the crackdown on Persian-speaking Christians. The IRCG was responsible for 12 of the 38 documented incidents of arrests of Christians or raids on their homes or house churches in 2021.

The report covering 2020-21 also notes the Iranian authorities' increased focus on cracking down on evangelism online, with Supreme Leader Ayatollah Ali Khamenei advancing a so-called "cyberarmy" to "protect" the Islamic republic from perceived threats.

Following the Islamic Revolution in 1979, the Twelver Jafari School of Shi'ite Islam was named as Iran's official religion under the constitution, which also states that all Iranian laws be derived and consistent with Islamic doctrine.

Three minority religions -- Zoroastrianism, Judaism, and Christianity -- are constitutionally recognized, but others are not and their followers are barred from holding services or possessing religious materials in Persian. That includes Christian coverts, who are not considered indigenous Christians.

"Indigenous Christians are mostly from Armenian, Assyrian, and Catholic churches, with some belonging to the Assemblies of God denomination," said Kiri Kankhwende of the U.K.-based religious advocacy organization Christian Solidarity Worldwide (CSW), which also contributed to the report. "While several converts have joined the Assemblies of God denomination, others belong to various evangelical house-church networks."

In February 2021, Iranian lawmakers amended Articles 499 and 500 of the Penal Code, paving the way for converts to be handed sentences of five years in prison for "engaging in propaganda that educates in a deviant way contrary to the holy religion of Islam."

CSW's Kankhwende told RFE/RL that the "situation remains bad and alarming" for Christian converts in Iran, and that the trend of arrests "is ongoing."

Last month alone, there was a raft of cases involving Christian converts.

Among them were the sentencing of three Christian Iranian men by the Rasht Revolutionary Court to five-year prison terms for "propaganda activities" related to their alleged teachings of a "deviant sect."

Two of the three members of the non-Trinitarian Church of Iran -- Ayub Purrezazadeh and Ahmad Sarparast -- were arrested in September in an IRGC raid on their house church. The third, Morteza Mashoodkari, was arrested the same month at his home.

Article 18 said that efforts by prosecutors to cast the three as "Satan-worshippers" due to their interpretation of the Trinity appeared to be "an obvious attempt to vilify the group and lessen public sympathy for them."

Fariba Dalir, a 51-year-old Christian convert who was arrested in the summer of 2021 along with six others, began serving a two-year sentence on April 16 for "acting against national security by establishing and leading an evangelical Christian church."

Dalir was sent to Tehran's notorious Evin prison the day before Easter. Four of the others, including her husband, were sentenced to 10 months in prison for membership of the banned church.

Another woman, Sakineh (Mehri) Behjati, was sent the same day to serve a two-year prison sentence at Evin prison on charges of "acting against national security" through her involvement with a house church. She was reportedly later allowed to transfer to another facility in the northern city of Rasht so she could be closer to her young child.

Following the arrest of Christian convert Rahmat Rostamipur in Bandar Anzali, a city on the Caspian Sea, on April 20 by 12 Intelligence Ministry agents, his wife was also summoned and interrogated and materials including Bibles were taken from their home, according to RFE/RL's Radio Farda. Rostamipour has yet to be formally charged with a crime.

And in late April, an Iranian Christian pastor who was initially sentenced to death for "apostasy" but subsequently given a reduced sentence for promoting "Zionist Christianity," was returned to prison after a brief furlough following a coronavirus outbreak in his ward at Evin prison.

The UN's Working Group on Arbitrary Detention has criticized the imprisonment of Yusef Nadarkhani of the Protestant Evangelical Church of Iran. It said Nadarkhani was legitimately exercising his religious freedoms, was discriminated against, and that he was not granted a fair trial or due process.

CRW's Kankhwende says that Christian converts charged under the revised Penal Code have limited legal recourse. "Depending on many circumstances, including financial resources, some are allowed to employ lawyers," she said. "But it is not always possible for the lawyers to represent their clients properly."

There have been cases of apparent leniency. In what was seen as a positive development, the Supreme Court ruled last year that the prison sentences of nine converts should be reviewed because their practicing of Christianity in a house church did not fit the verdict that they had harmed national security.

And some converts were temporarily released from prison last year over Christmas, and others, such as Pastor Nadarkhani, were granted furloughs due to the ongoing coronavirus pandemic that has harshly impacted Iran's overcrowded prisons.

But such incidents, according to Kankhwende, "depend largely at the discretion of the secret police and the supreme leader and are sometimes influenced by Iran's relationships with the international community and the impression it wishes to convey."

Iran has also been widely criticized abroad for the treatment of its recognized religious minorities, including obstructions that prevent members of faiths from attending services conducted in their native Persian.

Javaid Rehman, the UN special rapporteur on human rights in Iran, in his latest report expressed concern over the "continued repression of religious minorities, including through the forcible closing of houses of worship on national security grounds."

Rehman cited cases of pressure against Sunni Muslims, members of the Baha'i community, and the arrests of Christian converts despite the Iranian government's statements that religious minorities were respected and Christians, Jews, and Zoroastrians were constitutionally free to perform their religious rites.

The U.S. Commission on International Religious Freedom in 2022 redesignated Iran as a "country of particular concern," in part because it continues to "arrest, charge, sentence, and jail scores of Christians on charges including 'propaganda against the regime.'"

Numerous efforts have been launched in support of religious minorities in Iran, including a statement released in May by 25 Iranian Christians condemning Tehran's deprivation of Persian-speaking Christians' right to work.

Others, such as the online campaign #Place2Worship, decry the hurdles placed in the way of Iranian believers who want to attend religious services in their own language, giving them no option but to worship in private homes.

Until Iranian converts can practice their religion freely in their home country, many are expected to seek sanctuary abroad.

Atena Fooladi Helabad, whose experiences were documented by Article 18 in March, told the organization that after she and fellow church members were sentenced to one year in prison, she had no choice but to flee.

After seven years abroad, she said, "I feel like a child separated from its mother, having been separated from Iran."

With reporting by RFE/RL's Radio Farda.

Michael Scollon is a senior correspondent in RFE/RL's Central Newsroom in Prague.