The Savoy Declaration authors adopted, with a few alterations, the doctrinal definitions of the Westminster confession, reconstructing only the part relating to church government; the main effect of the Declaration of the Savoy assembly was to confirm the Westminster theology. There was the addition of a new chapter entitled Of the Gospel, and of the Extent of the Grace Thereof. Other changes include a replacement to chapters 30 and 31 of the Westminster Confession concerned with Congregational church government.
The authors of the Savoy Declaration adopted, with some adjustments, the doctrinal principles outlined in the Westminster Confession, specifically focusing on church governance. The main outcome of the Savoy assembly's declaration was to solidify Westminster theology.  They added a new chapter titled "Of the Gospel and the Extent of Grace Thereof." Additionally, they modified chapters 30 and 31 of the Westminster Confession concerning Congregational church government.