There are two great signs that Jesus Christ left to know whether it's the real Jesus Christ or not..
The first sign is Jesus Christ said himself that not one stone shall be left on top of another that shall not be thrown down..
Matthew 24:1-2,
1--"And Jesus went out, and departed from the temple: and his disciples came to him for to shew him the buildings of the temple.
2 And Jesus said unto them, See ye not all these things? verily I say unto you, There shall not be left here one stone upon another, that shall not be thrown down"
Well there's the temple wall in Jerusalem which the Jews call the Wailing Wall,
Which is still standing for a little over
2000 years and has one purpose..
As the real Lord Jesus Christ comes from the East to the West that wall shall come down..showing that the real Jesus Christ has come...
The other sign is at the coming of the real Jesus Christ everyone shall be changed from this body of flesh and blood to the Spirit, to meet the Lord Jesus Christ in the Spirit..
Now if someone comes, saying I am Christ and your still of flesh and blood that is not the real Jesus Christ....but the AntiChrist Satan, masquerading impersonating the real Jesus Christ..
As disciple Paul written in
1 Corinthians 15:51-52,
51--"Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed,
52 In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed"
Therefore at the coming of the real Jesus Christ everyone shall be changed from this body of flesh and blood to that of the Spirit....to meet The Lord Jesus Christ in the Spirit..