And they were all already saved by grace.
That is not what Jesus said in Matthew 25, and not what Jesus is going to say to us when we stand before him in judgement. He is going to do what he said. Read the earlier portion of Matthew 25 as well. He is the Prophet Moses foretold and he is going to do what he said he would do. The LORD thy God will raise up unto thee a Prophet from the midst of thee, of thy brethren, like unto me; unto him ye shall hearken; according to all that thou desiredst of the LORD thy God in Horeb in the day of the assembly, saying, Let me not hear again the voice of the LORD my God, neither let me see this great fire any more, that I die not. And the LORD said unto me, They have well spoken that which they have spoken. I will raise them up a Prophet from among their brethren, like unto thee, and will put my words in his mouth; and he shall speak unto them all that I shall command him. And it shall come to pass, that whosoever will not hearken unto my words which he shall speak in my name, I will require it of him.