Isa 27:12 And it shall come to pass in that day, that the LORD shall beat off from the channel of the river unto the stream of Egypt, and ye shall be gathered one by one, O ye children of Israel.
In that day, there shall be a gathering; the LORD shall beat off, thresh, the crop, it is harvest time. The grain is separated from the chaff, from Iraq and Egypt a people will be gathered, one by one; hear ye children of Israel.
John the Baptist introduced Jesus as the one to come.
Mat 3:11 I indeed baptize you with water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire:
Mat 3:12 Whose fan is in his hand, and he will thoroughly purge his floor, and gather his wheat into the garner; but he will burn up the chaff with unquenchable fire.
Isa 27:13 And it shall come to pass in that day, that the great trumpet shall be blown, and they shall come which were ready to perish in the land of Assyria, and the outcasts in the land of Egypt, and shall worship the LORD in the holy mount at Jerusalem.
At the trumpet of the Lord, many will be gathered from all nations unto the Lord.
Mat 24:29 Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken:
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.
Jesus comes to the world and people will either cry out in fear and will be removed by death or they will come in faith to the King of Kings. There will be no unbelievers at his return. There will be a harvest and a separation. We had better warn all, and we ourselves draw closer to our Lord, for he is coming back soon.