This is presumably (though not necessarily) a different angel than the one currently speaking to John (as referenced by the pronoun he
at the beginning of the verse). The angel in question is the one who formed a link in the chain of revelation first mentioned in Revelation 1:1: God – Jesus Christ – angel – John – the churches. As a servant of God (Revelation 1:1; Hebrews 1:14; Psalm 103:21–22) this angel characteristically functions in the background and so receives little mention. Nevertheless, as a link in the chain he played an essential role in bringing God’s revelation to John (and beyond him to the churches). Do recall that the word angel
denotes a messenger,
an envoy.
6 And he said to me, “These words are trustworthy and true. And the Lord, the God of the spirits of the prophets, has sent his angel to show his servants what must soon take place.”