Complex sentence: The Independents in the Army now argued that Charles was a "man of blood" who deserved to be punished, and that the outcome of the First English Civil War had been proof of God's judgment against Charles.
Split into simpler sentences: The Independents in the Army now argued that Charles was a "man of blood" who deserved to be punished. They argued that the outcome of the First English Civil War was proof of God's judgment against Charles.