"The restoration of all beings (apokatastasis) is the most important concept in Origen’s philosophy, and the touchstone by which he judges all other theories. His concept of universal restoration is based on equally strong Scriptural and Hellenistic philosophical grounds and is not original, as it can be traced back to Heraclitus, who stated that “the beginning and end are common” (Fragment B 103, tr. J. Barnes 1987, p. 115). Considering that Origen’s later opponents based their charges of heresy largely on this aspect of his teaching, it is surprising to see how well-grounded in scripture this doctrine really is. Origen’s main biblical proof-text is 1 Corinthians 15:25-28, especially verse 28, which speaks of the time “when all things shall be subdued unto him [Christ], then shall the Son also himself be subject unto him that put all things under him, that God may be all in all” (KJV, my emphasis). This scriptural notion of God being “all in all” (panta en pasin) is a strong theological support for his theory of apokatastasis. There are, of course, numerous other passages in scripture that contradict this notion, but we must remember that Origen’s strength resided in his philosophical ability to use reason and dialectic in support of humane doctrines, not in the ability to use scripture in support of dogmatical and anti-humanistic arguments. Origen imagined salvation not in terms of the saved rejoicing in heaven and the damned suffering in hell, but as a reunion of all souls with God."Source.