“Faith is, as St. Augustine teaches, born of will, not compulsion. A person can only be attracted into Christianity: he can never be forced. If a person is forced to be baptized, it is useless for engendering true faith, except in a baby. An adult must be able to answer personally for his own beliefs and desires. To profess faith falsely is to prevent true salvation. If the message of Christ and the burden of his light yoke were preached to the obdurate Saxons as keenly as demands for taxes and legal punishments are being imposed, then perhaps they would not reject the whole idea of Christian baptism. Teachers of Christianity must be educated in the example of the apostles. They must be preachers, not predators, trusting in the goodness of God alone.”
Alcuin of York to Charlemagne*
Charlemagne abolished the death penalty for paganism in 797.
*source: A Mind Intent on God: The Prayers and Spiritual Writings of Alcuin by Douglas Dales