Rev 3:1-6

THE SPIRIT 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 Yihvah 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.
Wake up, and establish the things that remain, which were ready to die, for I have found no works of yours perfected before my God. 3 Remember therefore how you have received and heard. Keep it, and repent. If therefore you won’t watch, I will come as a thief, and you won’t know what hour I will come on you. 4 Nevertheless you have a few names in Sardis that did not defile their garments. They will walk with me in white, for they are worthy.  He who overcomes will be arrayed like this in white garments, and I will in no way blot his name out of the book of life, and I will confess his name before my Father, and before his angels. 6 He who has an ear, let him hear what the Spirit says to the assemblies.
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.