Apocatastasis (also spelled "Apokatastasis") is a Greek word that means "Restoration." In Christian theology, Apocatastasis is the doctrine that Hell is not eternal, but a tool of divine teaching and correction, akin to Purgatory. Apocatastasis maintains that all moral creatures—angels, humans, and devils—will eventually come to a harmony in God's kingdom. Apocatastasis was formally pronounced Anathema by the Synod of Constantinople in 543 AD.