Think about it a moment. A man who can scientifically prove he lived 2000 years ago... DNA / blood content / whatever showing up on the scene, would be able to convince everyone he is who he claims to be... everyone but the Spirit-filled believers in Jesus Christ.
Revelation 13 (AV)
1And I stood upon the sand of the sea, and saw a beast rise up out of the sea, having seven heads and ten horns, and upon his horns ten crowns, and upon his heads the name of blasphemy.
2And the beast which I saw was like unto a leopard, and his feet were as the feet of a bear, and his mouth as the mouth of a lion: and the dragon gave him his power, and his seat, and great authority.
3And I saw one of his heads as it were wounded to death; and his deadly wound was healed: and all the world wondered after the beast.
4And they worshipped the dragon which gave power unto the beast: and they worshipped the beast, saying, Who is like unto the beast? who is able to make war with him?
5And there was given unto him a mouth speaking great things and blasphemies; and power was given unto him to continue forty and two months.
6And he opened his mouth in blasphemy against God, to blaspheme his name, and his tabernacle, and them that dwell in heaven.
7And it was given unto him to make war with the saints, and to overcome them: and power was given him over all kindreds, and tongues, and nations.
8And all that dwell upon the earth shall worship him, whose names are not written in the book of life of the Lamb slain from the foundation of the world.
9If any man have an ear, let him hear.
10He that leadeth into captivity shall go into captivity: he that killeth with the sword must be killed with the sword. Here is the patience and the faith of the saints.
Daniel 11:37 (AV)
37Neither shall he regard the God of his fathers, nor the desire of women, nor regard any god: for he shall magnify himself above all.
2 Thessalonians 2:3–4 (AV)
3Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;
4Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God.
Matthew 24:15–27 (AV)
15When ye therefore shall see the abomination of desolation, spoken of by Daniel the prophet, stand in the holy place, (whoso readeth, let him understand)
16Then let them which be in Judaea flee into the mountains:
17Let him which is on the housetop not come down to take any thing out of his house:
18Neither let him which is in the field return back to take his clothes.
19And woe unto them that are with child, and to them that give suck in those days!
20But pray ye that your flight be not in the winter, neither on the sabbath day:
21For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.
22And except those days should be shortened, there should no flesh be saved: but for the elect’s sake those days shall be shortened.
23Then if any man shall say unto you, Lo, here is Christ, or there; believe it not.
24For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect.
25Behold, I have told you before.
26Wherefore if they shall say unto you, Behold, he is in the desert; go not forth: behold, he is in the secret chambers; believe it not.
27For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be.
Acts 1:9–11 (AV)
9And when he had spoken these things, while they beheld, he was taken up; and a cloud received him out of their sight.
10And while they looked stedfastly toward heaven as he went up, behold, two men stood by them in white apparel;
11Which also said, Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven.
Revelation 1:7 (AV)
7Behold, he cometh with clouds; and every eye shall see him, and they also which pierced him: and all kindreds of the earth shall wail because of him. Even so, Amen.
Matthew 24:30 (AV)
30And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.
1 Thessalonians 4:17 (AV)
17Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord.