In this five-week series, we will examine the histories of four men who made significant contributions to the repentance and reformation of God’s church. Martin Luther, William Tyndale, John Calvin, and John Knox fought hard to help the church keep ‘the main thing’ the main thing. God worked through them to once again establish the powerful gospel of salvation by grace alone through faith alone in Christ alone, according to the authority of the scriptures as the anchor of His church.