Pastor Sergey Perkhalskiy made sure to convert his Christian Hope Church in Kyiv to a bomb shelter before quitting the capital last week. He faced a tough choice: stay with his congregation or leave to protect his family, including his elderly parents. Either way, he says, "we overcome fear by helping each other." Mr. Perkhalskiy’s church is Pentecostal. Like many Protestant clergy, he knows today's trauma is a foretaste of tomorrow's wreckage should Vladimir Putin conquer Ukraine.