^15:6and the seven angels who had the seven plagues came out of the temple, clothed in linen, clean and bright, and girded around their breasts with golden girdles.

and the seven ANGELS

Seven denotes completion; with the seven bowls these seven angels are going to carry, we will see the completion of God's wrath (verse 1).

This is the third set of seven angels. The first set were the angels to the seven churches (Revelation 2). The second set were the trumpet blowers (Revelation 8:6). This set has a different job to do as we will see.

who had the seven PLAGUES

While there is not a one to one correspondence to the plagues God sent via Moses upon Egypt, this indicates that PLAGUES are real and probably fall into categories:

1. Water into blood
2. Removal of animals (livestock and fish) for food
3. Removal of grains and vegetables for food
4. Fire from above
5. Physical ailments (sores and boils)
6. Earthquakes
7. Foul spirits (frogs)

Each category is a study unto itself.

came out of the temple,

This is really the Holy of Holies, Naos in Greek, part of the temple. Thus these are angelic priest types. Compare to the earthly high priests (Exodus 28:28-30).

clothed in linen, clean and bright,

Linen denotes righteousness. It is this righteousness about which the song was sung (verse 3) and will be the garment of the bride, the believers, at the wedding supper (Revelation 19:8).

Compare how Daniel saw this Son of Man in his vision (Daniel 10:5-7).

and girded around their breasts with golden girdles.

Christ, as High Priest in heaven (Hebrews 5:1-10) is dressed this way (Revelation 1:13).

The girdle indicates service and a golden girdle denotes Godly service. Also the girdle (or sash) had some protection value. Note what it is that these 7 angels will be assigned to do. They will be protected by God Himself.