When the Son of Man comes in his glory, and all the angels with him, then he will sit on the throne of his glory. All the nations will be gathered before him, and will separate people one from another as a shepherd separates the sheep from the goats, and he will put the sheep at his right hand and the goats at the left. Then the king will say to those at the right hand, ‘Come, you that are blessed by my Father, inherit the kingdom prepared for you from the foundation of the world.’
Then he will say to those at his left hand, “You are the accursed, depart from me into the eternal file prepared for the devil and his angels.”
I think the key to understanding this powerful passage is: Who is "the Son of Man" and when will he "come into his glory"? In the context of Jesus' teaching and example, the Son of Man is the Christ, the true spiritual identity of each person. The Christ comes into his glory when we are fully expressing that Christ Presence—fully one with our spiritual Power—as Jesus was able to accomplish and demonstrate. When that happens, we will see through the eyes of the Christ, inspired by divine ideas ("all the angels"). We will discern clearly the working of the Law. We'll understand that choices we make to express unconditional love create the kingdom of heaven, and fear-based choices to refuse opportunities for love create life experiences that are as fear-based and challenging as our choices. A God of infinite love does not judge us, but lovingly makes us aware that our choices have consequences. And the painful consequences of negative choices are "eternal" only if we insist on making the same choices, over and over again.