People come to Jesus in "nations" (earthly groups) but they leave the Judgment Throne in only two groups: Sheeps and Goats--believers and unbelievers.
On that I have to disagree.... He specifically did not separate them by who believed in Him and who did not... That was NOT Jesus's lesson in this Scripture?
If you noticed, BOTH GROUPS called him LORD? Both of those groups knew Jesus as Lord, both of those groups asked of Jesus, "but when did we do this for/to you?" And He said, basically, however you treated those that He mentioned, (the sick, poor, stranger, imprisoned) you treated Him...???
Sweet Sue is right, I think. Only believers inherit the kingdom of God. Calling someone "lord" matters not a whit to people who could care less about that someone, unless they think that doing so might reward them somehow.
I can see that point of view, based on other readings of Scripture regarding who is saved, and how some churches have interpreted such over the centuries of Christianity.
But they did not just call Him Lord, they knew Him in the sense that they are asking Christ basically, ''...when in the world did we deny you food to eat or water to drink etc...?'' It gave a sense in the passage reading, that they knew him more than just at that moment of the Hour of Judgement.
Also, not one single peep from Jesus, on Judgement Day, to all the people in all the Nations of the world itself that He is judging, about whether whom ever so 'Believeth in Him'' or not....? Why Not? IF that is one of the most important parts of Christianity... again, why not mention it or even hint of it, at the Last Judgement?
I just think, there is much more to this Scripture, than we understand on the surface, if we contemplate on it, in depth... piece by piece of what is going on in this scene of the last judgement of Christ...