15:1 And I saw another sign in heaven, great and marvelous, seven angels having the seven last plagues; for in them is filled up the wrath of gods.
The seven angels signify the spiritualized energies of the seven chakras of the individual. The seven plagues symbolize the accumulated karma of the individual. This can also be applied to the planetary chakras and the human race as a whole, if we are speaking about the larger scheme of things.
15:2 And I saw as it were a sea of glass mingled with fire: and them that had gotten the victory over the beast, and over his image, and over his mark, and over the number of his name, stand on the sea of glass, having the harps of gods.
The souls that are victorious over the Beast signify the purified mind and soul of the individual. Globally, they are the people on the planet that regularly practice spiritual purification techniques.
15:3 And they sing the song of Moses the servant of the gods, and the song of the Lamb, saying, Great and marvelous are thy works, YHVH God of Hosts; just and true are thy ways, thou King of the Saints.
The Song of Moses and the Song of the Lamb both symbolize the same thing: Victory over the lower forces in the psyche.
15:4 Who shall not fear thee, O YHVH, and glorify thy name? for thou only art holy: for all nations shall come and worship before thee; for thy judgments are made manifest.
This question signifies the spiritual thoughts empowering the Spiritual Consciousness of the individual. On a larger scale, they are the spiritual people empowering the Divine through their consciousness.
15:5 And after that I looked, and, behold, the temple of the tabernacle of the testimony in heaven was opened:
15:6 And the seven angels came out of the temple, having the seven plagues, clothed in pure and white linen, and having their breasts girded with golden girdles.
The seven plagues symbolize the purification and tribulation experienced by the individual in order to overcome their negative karma (errors caused by going against their Divine Nature or interfering with the spiritual development of others). Gold is a color symbolizing spiritual perfection. The same symbolism is used in Alchemy.
15:7 And one of the four beasts gave unto the seven angels seven golden vials full of the wrath of gods, who liveth for ever and ever.
The power of the Spiritual Consciousness controls the karma of the individual and, on a larger scale, the human race.
15:8 And the temple was filled with smoke from the glory of gods, and from his power; and no man was able to enter into the temple, till the seven plagues of the seven angels were fulfilled.
No one can complete the process of enlightenment and become a savior to themselves or a guide for others until they have purified themselves of their own negative karma.