Effectual prayer
occurs in Authorized Version, James 5:16. The Revised Version
renders appropriately: "The supplication of a righteous man
availeth much in its working", i.e., "it moves the hand of Him
who moves the world."
Bibliography Information Easton, Matthew George. M.A., D.D., "Definition for 'Effectual prayer' Eastons Bible Dictionary". bible-history.com - Eastons; 1897.