While Congolese asylum-seekers make a desperate journey north, a scrappy network of Christians answers the call to help. Temperatures in the Chihuahuan Desert lowlands were steadily hitting triple digits in the last days of June as a small group of Congolese men, women, and children waded into the Rio Grande in the Mexican city of Ciudad Acuña. Midway across a weary, 31-year-old man named Gauthier looked up toward the riverbank on the other side, in Del Rio, Texas. Several US Customs and Border Patrol were waiting. Waiting, he hoped, to guide him and his fellow travelers toward asylum in the…