She first entered a church on a visit to Turkey. She remembers feeling a sense of calm so overpowering that she purchased a small Bible. She wrapped it in her clothes and smuggled it back to her hometown, Isfahan, in central Iran.

Artemis Ghasemzadeh’s conversion from Islam to Christianity evolved over a few years starting in 2019, through an Iranian network of underground churches and secret online classes. Three years ago, she was baptized and, in her words, “reborn.”

Converting was colossally risky. While Christians born into the faith are free to practice, Iran’s Shariah laws state that abandoning Islam for another religion is considered blasphemy, punishable by death. Some members of her Bible-study group were arrested.

So in December, Ms. Ghasemzadeh set out for the United States.

“I wanted to live freely, to live without fear, to live without someone wanting to kill me,” Ms. Ghasemzadeh, 27, said in a series of phone interviews.

Her journey has landed her in a migrant detention camp on the outskirts of the Darién jungle in Panama. She and nine other Iranian Christian converts, three of them children, are among dozens detained at the Saint Vincente camp. Their fate remains uncertain.