The following is an excerpt from
The MacArthur New Testament Commentary on Matthew 25.
All the nations will be gathered before Him; and and He will separate them from one another, as the shepherd separates the sheep from the goats; and He will put the sheep on His right, and the goats on the left. (Matthew 25:32-33)
The subjects of Christ’s judgment will be all the nations. Ethna (nations) has the basic meaning of peoples and here refers to every person alive on earth when the Lord returns. Although He will have taken all believers into heaven at the Rapture, during the following seven years of the Tribulation many other people will come to believe in Him. During that dreadful time, multitudes of Gentiles (see Rev. 7:9, 14), as well as all surviving Jews (Rom. 11:26), will be brought to faith in Christ.
As Jesus makes clear later in this passage, those who are alive on earth when He returns will include both saved and unsaved, represented by the sheep and the goats, respectively. And those two separate peoples will have two separate destinies. The believers will be ushered into the kingdom and the unbelievers into eternal punishment (Matt. 25:46).
The process of Christ’s judgment will include the absolute and unerring separation of the saved from the unsaved. When all the nations and peoples of the earth will have been gathered before Him at His return, the Lord Jesus Christ will separate them from one another, as the shepherd separates the sheep from the goats.
In the ancient Near East, as in much of that land still today, sheep and goats are frequently herded together. But sheep are docile, gentle creatures, whereas goats are unruly and rambunctious and can easily upset the sheep. Because they do not feed or rest well together, the shepherd often separates them for grazing and for sleeping at night.
In a similar way the Lord Jesus Christ will separate believers from unbelievers when He returns to establish His millennial kingdom. He will put the believing sheep on His right, the place of favor and blessing. But the unbelieving goats He will put on the left, the place of disfavor and rejection.
In ancient biblical times, a father’s blessing was extremely important, because it determined who would receive the major part of the inheritance. When Jacob was about to bless his two grandsons, Ephraim and Manasseh, he was careful to place his right hand on the one who would receive the inheritance. Because the major blessing normally went to the eldest son, Manasseh was placed on Jacob’s right and Ephraim on his left. But when the time for blessing came, Jacob crossed his hands so that his right hand was on Ephraim’s head rather than Manasseh’s. Against Joseph’s objection, Jacob insisted on giving the major blessing to Ephraim, because God had chosen him over his brother (Gen. 48:8–20).