We know from Matthew 25 that when…
the Son of Man comes in his glory, and all the angels with him, he will sit on his glorious throne. All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. He will put the sheep on his right and the goats on his left.
“Then the King will say to those on his right, ‘Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world
But what is referenced on that day? Well, Jesus says it’s because—
I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in, I needed clothes and you clothed me, I was sick and you looked after me, I was in prison and you came to visit me.
It’s Christ’s union with them, and they’re working for him in the church that explains all that. Every action they have committed, often unknown to them, has been credited as righteousness to them. The Lord Jesus takes it as a benefit to him so that every hungry church member who is fed, every thirsty church member who is given something to drink, every visitor to the church who is invited into a home, every church member who is lacking clothes and is given clothes, every sick church member that is cared for, every church member who is visited—these things have been done for Christ. Christ credits those things as things done for Him because of union with his church. That is what our hope will be on judgment day.