“From Tertullian to the Reformation, there is a significant Christian tradition that affirms religious freedom. Fourth-century Christian writer Lactantius argues that “religion cannot be imposed by force.” The fourth-century “protocols of Milan,” issued by the Roman emperor Constantine, granted Romans “freedom” to “all men to follow whatever religion each wishes.” Alcuin, an advisor to Charlemagne, tells the emperor that “faith arises from the will, not from compulsion…you can persuade a man to believe, but you cannot force him.” This counsel was necessary because Frankish kings were forcing the conversions of various pagan tribal groups in central Europe at the edge of a sword.”
Read more at: Thank Christianity, Not Secularism, for Religious Liberty | The American Conservative