Revelation 3:1-6

Seven_churches_of_asia
The Spirit of Christ to Sardis

1 “And to the angel of the assembly in Sardis write: He who has the seven Spirits of God, and the seven stars says these things: “I know your works, that you have a reputation of being alive, but you are dead.

Rev 3:1
He who has the seven Spirits of God and the seven stars – the seven stars are the Angels of the Seven Churches, see Rev 1:20.  The Spirit of Christ, as the Archangel, the Ruler of the Angels, has the seven Spirits of God in His hand, see Zech 4:10. These Spirits are manifest as seven Angels or messengers. The Angels (shown as horse riders) are the manifestations of the spirits (horses) who report to the Angel of YHVH in Zech 1:10. Through this, we can understand the relationship between a Spirit, and an Angel or Messenger. The Spirit of Christ in this passage is also manifest as an Angel, a Messenger. And in fact, all of the Spirits of God may be manifest as Angels, or Messengers. The number seven refers to the “complete” number of Spirits of God.

4Nevertheless you have a few names in Sardis that did not defile their garments. They will walk with me in white, for they are worthy. 

Rev 3:4
I will come like a thief – Christ gave us many warnings that His return would be like a thief in the night, eg Matt 24:43.