Puzzled About Revelation, Part 57: Fire & Water (Rev. 15)

Join me this week as we continue our study in Revelation 15.
John saw yet another vision: seven angels with the seven last plagues, a sea of glass mixed with fire, and a multitude of those who were victorious over the beast standing next to the sea and singing the Song of Moses.
What do these visions means and what encouragement and instruction can we gain from them? Tune in to find out!