of inactivity. At Calvin's urging Knox became pastor of the English congregation at Frankfurt in 1554. The congregation soon divided over the question of revising the Book of Common Prayer or substituting a new liturgy. Knox chose to withdraw and return to Geneva in 1555.
In September 1555 he went back to Scotland for nine months and openly preached Protestant doctrine. He encouraged Protestant leaders to abstain from Mass and to instead celebrate Communion with a Reformed ritual. He was summoned to
