Sure. A few hundred years after Christ, they were still considered early church fathers i suppose. Still, it is a later text added, officially, sometime after the rest of it.
Revelation was written down by John of Patmos roughly a century after the crucifixion of Christ. It is his recount of a prophetic vision he received. It's heavy in symbolism and metaphor. There's no way to understand what most of it means without spiritual discernment, and it may be that some of its secrets are not meant to be revealed yet. Reading it without praying for guidance and trying to understand it will get you nowhere.