The document that bishop Palmer is likely referring to is the Joint Declaration on the Doctrine of Justification, created in 1999 by the Lutheran World Federation and the Catholic Church and joined by the World Methodist Council in 2006 and the World Communion of Reformed Churches in 2017. The Anglican Communion also "Welcomed and affirmed the substance of the Joint Declaration..." The doctrinedocument attempts to address the disagreements between Catholics and Lutherans on the topic of justification, which is generally seen as the root issue of the Reformation.