1 Thessalonians 1:9-10
New King James Version
9 For they themselves declare concerning us what manner of entry we had to you, and how you turned to God from idols to serve the living and true God, 10 and to wait for His Son from heaven, whom He raised from the dead,
even Jesus who delivers us from the wrath to come.
The Day of the Lord is the return of Christ, it means the destruction of the wicked world and our salvation from it, and the kingdoms of the world will be given to us and taken away from them and they will have nothing, their part will be in the Lake of Fire that will burn with fire and brimstone and consume them forever. When Jesus told us the meek shall inherit the earth, this is what He meant. Before this though the devil and his false prophet and beast world system make war on the saints of God and prevail against them until God says enough and it is the time for the saints to possess the greatness of the kingdoms under the whole heaven. God made the earth to be inhabited and all of it will be given to us.
27
Then the kingdom and dominion,
And the greatness of the kingdoms under the whole heaven,
Shall be given to the people, the saints of the Most High
Daniel 7
21 “I was watching; and the same horn was making war against the saints, and prevailing against them, 22 until the Ancient of Days came, and a judgment was made in favor of the saints of the Most High, and the time came for the saints to possess the kingdom.
23 “Thus he said:
‘The fourth beast shall be
A fourth kingdom on earth,
Which shall be different from all
other kingdoms,
And shall devour the whole earth,
Trample it and break it in pieces.
24 The ten horns
are ten kings
Who shall arise from this kingdom.
And another shall rise after them;
He shall be different from the first
ones,
And shall subdue three kings.
25 He shall speak
pompous words against the Most High,
Shall persecute[
j] the saints of the Most High,
And shall intend to change times and law.
Then
the saints shall be given into his hand
For a time and times and half a time.
26 ‘But the court shall be seated,
And they shall take away his dominion,
To consume and destroy
it forever.
27 Then the kingdom and dominion,
And the greatness of the kingdoms under the whole heaven,
Shall be given to the people, the saints of the Most High.
1 Thessalonians 5, that Day is a sudden destruction from the Almighty which overtakes them like a thief. And for them they have no escape and no idea of the coming sudden wrath. But it wont take us unawares, as we have believed the warnings from God, not that we will know the Day when it happens, But God has prepared us to be expecting this.
But concerning the times and the seasons, brethren, you have no need that I should write to you. 2 For you yourselves know perfectly that the day of the Lord so comes as a thief in the night. 3 For when they say, “Peace and safety!” then sudden destruction comes upon them, as labor pains upon a pregnant woman. And they shall not escape. 4 But you, brethren, are not in darkness, so that this Day should overtake you as a thief. 5 You are all sons of light and sons of the day. We are not of the night nor of darkness. 6 Therefore let us not sleep, as others
do, but let us watch and be [
a]sober. 7 For those who sleep, sleep at night, and those who get drunk are drunk at night. 8 But let us who are of the day be sober, putting on the breastplate of faith and love, and
as a helmet the hope of salvation.
9 For God did not appoint us to wrath, but to obtain salvation through our Lord Jesus Christ, 10 who died for us, that whether we wake or sleep, we should live together with Him.