Summary: A Song of Ice and Fire is essentially retelling the story of Revelation 12-19. Judging from passages in the scripture, there will be two Targaryen invasions, followed by a series of plagues. Finally, Jon Snow will lead the White Walkers to destroy Targaryen forces, and ultimately rule over Westeros. Reasoning: It's all laid out rather nicely here by Reddit user alexwebb2. Past events have mirrored passages from the scripture, such as Robert's Rebellion, and the belief here is that later passages will predict the future of the series. Certain events in Revelations, such as a red dragon with seven heads, provides imagery strikingly similar to that in Game of Thrones. Additionally, many of the plot threads that could run parallel with Revelations in this theory seem to fit, such as Daenerys invading a kingdom with dragons, and references to a white army. Likelihood: It's very unlikely that the events will follow Revelations quite as closely as this theory seems to imagine. Martin hasn't just taken inspiration from biblical scripture, but also that of medieval history, Norse mythology and much more. While there are likely to be even more allusions in the future, there's no reason for the writer to tie himself down in this manner.
