Backed by the full force of federal law, the Revolutionary Government confiscated all Church property, including hospitals, monasteries, convents, and schools. Priests were forbidden to wear their clerics in public. They were not allowed to express opinions on politics, even in private conversation. They could not seek justice in the Mexican courts. To take a religious vow became a criminal act. All foreign clergy were deported.

When the Cristeros took up arms in January 1927, they had very few arms to take up, only their battle cry, "Viva Cristo Rey!" The uprising occurred almost simultaneously in small towns and villages in a dozen western states including Zacatecas, Jalisco, Guanajuato, Durango, Michoacan, and Colima. Hundreds of small, poorly organized bands of sharecroppers and rancheros bearing machetes and a few rifles took over local municipalities by disarming the garrisons at federal outposts, as well as local police and militia units.