Ten differences between Orthodox and Catholicism.
1. Orthodox reject inheritability of sin. Death and suffering are human nature, we only don't suffer them when partaking in perfect synergism with God's energies, which we haven't since the fall.
2. The Orthodox reject the "satisfaction theory of atonement". The Orthodox subscribe to "Christus Victor" (the idea of atonement illustrated in The Lion, the Witch and the Wardrobe).
3. Hell in Orthodoxy is not separation from God. Hell, like heaven, is experiencing the full radiance of God's light and presence, but with a negative relationship so that it is like fire.
4. The Orthodox reject the idea that our understanding of dogma develops. The idea is to keep the exact same understanding the Apostles have, invented terminology is not meant to develop the understanding, but to PROTECT it from being "developed".
5. Catholics define usury as excessive interest, Orthodox define usury as any interest.
6. The Orthodox reject the Catholic idea of supererogation.
7. The Orthodox reject Purgatory. The Orthodox do, however, distinguish Sheol (called "Hades" in Greek) from Gehenna.
8. Orthodoxy places enormous emphasis on fasting, in fact more than half the days of the year involve some sort of fast. And there are even some days which are total fasts, no intake, period. Two consistent fast days (almost every Wednesday and Friday, no meat, dairy, eggs, fish, oils or wine) trace back at least to the Didache.
9. Orthodox draw most of their priests from the married laity, but most of their bishops from monks.
10. Infants can and do receive Holy Communion.