The Greek text of 1 Tim. 3:16 according to the Textus Receptus of Robert Estienne reads:

Notably, it begins with the word Θεὸς. The King James Version (1769) translates this into English as:

And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory. ^{KJV, 1769}

However, some other English translations offer a different translation. For example, the NASB:

By common confession, great is the mystery of godliness:
He who was revealed in the flesh,
Was vindicated in the Spirit,
Seen by angels,
Proclaimed among the nations,
Believed on in the world,
Taken up in glory. ^NASB

What is the reason for the difference in translations? What is the implication if the King James Version yields the correct translation?