Mat 24:30 And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven
with power and great glory.
Mat 24:31 And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other.
Parallel passages; Mark 13:26, Luke 21:27
1Th 2:19 For what is our hope, or joy, or crown of rejoicing?
Are not even ye in the presence of our Lord Jesus Christ at his coming?
1Th 2:20 For ye are our glory and joy.
Paul when writing to the Christian Thessalonians says “ye are our glory and joy”. In the Gospels Jesus says “Son of man coming in the clouds of heaven with power and great glory”. I’m not sure if Paul meant by the glory but maybe he meant the glory described in Matthew.
The Christians we know are in the clouds when the Lord Jesus comes back, but so are the angels, for the angels are stated as coming with the Lord as well
Saints 2Th 1:10 when he comes on that day to be glorified in his saints, and to be marveled at among all who have believed, because our testimony to you was believed.
1Th 4:17 Then we who are alive, who are left, will be caught up together with them in the clouds to meet the Lord in the air, and so we will always be with the Lord.
Here the Son of Man comes with Holy Angels. Mat 25:31 When the Son of man shall come in his glory, and all the
holy angels with him, then shall he sit upon the throne of his glory.
2Th 1:7 And to you who are troubled rest with us, when the Lord Jesus shall be revealed from heaven
with his mighty angels,
In Jude the Lord Jesus comes with holy ones. Jud 1:14 It was also about these that Enoch, the seventh from Adam, prophesied, saying, "Behold, the Lord came
with ten thousands of his holy ones,
Jud 1:15 to execute judgment on all and to convict all the ungodly of all their deeds of ungodliness that they have committed in such an ungodly way, and of all the harsh things that ungodly sinners have spoken against him."
In ZechariahZec 14:5 And you shall flee to the valley of my mountains, for the valley of the mountains shall reach to Azal. And you shall flee as you fled from the earthquake in the days of Uzziah king of Judah. Then the LORD my God will come, and
all the holy ones with him.
In Summary The Lord comes with
1. Power and great glory
2. The saints
3. Holy Angels
4. Mighty Angels
5. Holy Ones
If you look at the meaning of each word you will see they are contadictory and they are similar except power and great glory.
(saint) hag'-ee-os
From ἅγος hagos (an awful thing) compare G53, [H2282]; sacred (physically pure, morally blameless or religious, ceremonially consecrated): - (most) holy (one, thing), saint.
(Angels) ang'-el-os
From ἀγγέλλω aggellō (probably derived from G71; compare G34; to bring tidings); a messenger; especially an “angel”; by implication a pastor: - angel, messenger.
As you can see by definition an angel can be a saint but not necessarily i.e. Satan’s angels are not saints. However the Angels who come with the Lord Jesus are Holy Angels and can even be called saints.
Can Christians be Angels?Why not. We do not think of our selves as angels, or at least I don’t but in the resurrection when the saints come back there is no reason to say we can not be called angels.
The Lord himself talks about the resurrection and says those who are resurrected are as the angels of God in heaven.
Mat 22:30 For in the resurrection they neither marry, nor are given in marriage, but are as the angels of God in heaven.
Paul says we must change and we will in a twinkling of an eye.
1Co 15:52 In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.
1Co 15:53 For this corruptible must put on incorruption, and this mortal must put on immortality.
I wouldn’t rule out the possibility that the Christians of this world and the saints of the Old Testament and the angels who stayed in heaven are all after the resurrection the angels of heaven. As you can see the Bible uses these terms interchangeably when describing those who are with the Lord when he returns in the clouds, yet never uses two descriptions in conjunction which means they are likely the same. I.e. never uses Holy angels and saints in the clouds.
When speaking or writing we don't describe two things that are the same two differnt ways in conjunction. For example if I told you that I was coming to visit you on Saturday and the last day of the week that would just be confusing, because they are actually the same thing. So thats why I say that the fact that they are never described in conjunction but interchagably is because they are probably the same.