Look, you called me the devil earlier and I consider you to be mentally unstable. Just leave me alone.
With your ideas, you would call Jesus Christ mentally unstable. But He will be talking to you when He says this.
Matthew 25:31-46 31 "When the Son of Man comes in His glory, and all the holy angels with Him, then He will sit on the throne of His glory. 32 All the nations will be gathered before Him, and He will separate them one from another, as a shepherd divides his sheep from the goats. 33 And He will set the sheep on His right hand, but the goats on the left. 34 Then the King will say to those on His right hand, 'Come, you blessed of My Father, inherit the kingdom prepared for you from the foundation of the world: 35 for I was hungry and you gave Me food; I was thirsty and you gave Me drink; I was a stranger and you took Me in; 36 I was naked and you clothed Me; I was sick and you visited Me; I was in prison and you came to Me.' 37 Then the righteous will answer Him, saying, 'Lord, when did we see You hungry and feed You, or thirsty and give You drink? 38 When did we see You a stranger and take You in, or naked and clothe You? 39 Or when did we see You sick, or in prison, and come to You?' 40 And the King will answer and say to them, 'Assuredly, I say to you, inasmuch as you did it to one of the least of these My brethren, you did it to Me.' 41 Then He will also say to those on the left hand, 'Depart from Me, you cursed, into the everlasting fire prepared for the devil and his angels: 42 for I was hungry and you gave Me no food; I was thirsty and you gave Me no drink; 43 I was a stranger and you did not take Me in, naked and you did not clothe Me, sick and in prison and you did not visit Me.' 44 Then they also will answer Him, saying, 'Lord, when did we see You hungry or thirsty or a stranger or naked or sick or in prison, and did not minister to You?' 45 Then He will answer them, saying, 'Assuredly, I say to you, inasmuch as you did not do it to one of the least of these, you did not do it to Me.' 46 And these will go away into everlasting punishment, but the righteous into eternal life."
That Kingdom that Jesus talks about is set up in Israel, ruling over all the nations. You won't be calling Jesus "mentally unstable" in "that day". You will be going into "everlasting punishment" -- as He says.