In this, the last installment of this series, I discuss three more rivals to early Orthodox Christianity, the Manicheans, the Hermeticists, and the Neo-Platonists. The first two could definitely be considered Gnostic, however, the last, Neo-Platonism, is more of a philosophy than a theology. I chose to include it though because it was not only in strong competition with Orthodoxy, but it also helped shape Christianity, as we know it today. Be sure to read all 4 parts of this series and my other articles on religion and beliefs.