Revelation 15:5,6

5  And after that I looked, and, behold, the temple of the tabernacle of the testimony in heaven was opened:

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.

After the full measure of tribulation saints are in heaven and singing songs of victory, the temple of the tabernacle of the testimony is opened in heaven. This is the Holy of Holies. The tabernacle made on earth was just a copy of what Moses was told was in heaven. The tabernacle of the testimony contained the “Ark of the Covenant”. The earthly copy contained the Ten Commandments, manna, and Aaron’s rod. The Ark seen in heaven will be a witness against the world because the world has now rejected everything in it.  They rejected the covenant in heaven that contains the Word of God (Jesus), the true bread of life (Jesus) and God’s choice for high priest (Jesus).

Out of the temple come the seven angels that have the task to bring the seven last plagues that will come on all those who reject the God of heaven and who worship the Beast. The white linen that the angels wear shows that these angels are righteous and stand in the presence of God. Their golden girdles indicate that these seven angels are priests in the heavenly temple and have full authority from God to carry out His commands.