Identify and explain an overarching theme found in Roger Williams's work.

An overarching theme in Roger Williams's work is religious freedom. He wrote about this in several works, including his famous The Bloudy Tenent of Persecution, for Cause of Conscience and his work The Bloudy Tenent Yet More Bloudy.
In Bloudy Tenent of Persecution, written in 1644, Williams calls for the separation of church and state, using the Bible to support his argument. He argued for the religious freedom of the various Protestant sects and argued for Catholics, Jews, Muslims and other "heretical" groups to be left free to worship as they wished. He based this assertion of religious freedom on Jesus's teaching that God would ultimately judge who was and was not righteous. If the state judged and persecuted people for their faith, the state usurped God's role. The state could, through poor decisions, harm the good "wheat" of the truly faithful followers of Christ.
Williams stated that the Bible condemned kings like Nebuchadnezzar who forced Jews to worship the gods of the state against their conscience. He quoted Paul to argue that the state should use only spiritual, not physical, weapons to convince unbelievers. Williams also thought the beast in Revelation was the symbol of state churches.
Williams wrote:
It is the will and command of God that, since the coming of his Son the Lord Jesus, a permission of the most Paganish, Jewish, Turkish, or anti-christian consciences and worships be granted to all men in all nations and countries : and they are only to be fought against with that sword which is only, in soul matters, able to conquer: to wit, the sword of God's Spirit, the word of God.
After he was attacked for arguing in favor of the separation of church and state, he repeated and elaborated on his arguments in The Bloudy Tenent Yet More Bloudy.
His arguments for religious freedom clearly found favor in the the United States, where freedom of religion was enshrined in the Constitution. Nevertheless, his ideas were radical for a time when church and state were tightly tied together and when the monarch was considered God's representative on earth.