When He comes to judge it will not be merely the circumscribed area of the earth in which He labored and revealed Himself; rather it will be all the nations and the empires of the world. The time of His second coming He knows not as man, but only as God. He will not tell it except in warning that it will be sudden, like lightning. He came as a “Man of Sorrows” then He shall come in His glory. The attributes of His suffering humanity will be necessary for His identification. Hence, after His Resurrection, He kept the scars. With Him will be the angels, and all the nations will be divided into two classes: sheep and goats. As He divided men on earth into two classes, namely, those who hated and those who loved Him, so He would divide them then. “I am the Good Shepherd,” He said of Himself. The title He would vindicate on the last day by a separation of His flock of sheep from the goats.
The sheep will hear themselves commended for loving service to Him, even when it was unconscious service. There are many more people loving and serving Him than one suspects. It would seem that the most surprised of all will be the social workers who will ask, “When was it that we saw Thee hungry? Was it case #643?” The wicked, on the other hand, will find themselves refusing Him when they refused to do anything for their fellow man in His name.
– from Life of Christ (1958)