BROOKLYN, N.Y.—The two women’s lives have run in parallel with each other, despite their never having met before. Both were born in China and later fled to New York after nearly two decades of sustained harassment and arrests. Both were detained while pregnant and were threatened with forcible abortion. And both declined the one thing the authorities wanted them to do: renounce their belief. They are both adherents of Falun Gong, a meditation practice grounded in the principles of truthfulness, compassion, and forbearance, which became hugely popular in China three decades ago. In 1999, after the Chinese Communist Party (CCP) labeled the practice a threat, Peng Zhaoli from Chongqing in southwestern China and Xia Baozhen from Shanghai—both in their 20s—became targets for local police, along with the other 70 million to 100 million Falun Gong adherents all over China. Peng and Xia, now in their late 40s, joined a nearly 1,000-strong …