The notion that Jesus "returned invisibly" never made sense to me, even when I was a true believer. Matthew chapter 24 just confirms that. When the disciples asked Jesus "when will these things be and what will be the sign of your COMING and of the end of the age?" I hardly think they were asking him 'please tell us when you'll be returning invisibly so we can start to make predictions and speculation on prophecy.' They expected a VISIBLE return. That it would not be an "invisible", secret return is clearly shown in vs. 30. After giving all the signs that would lead up to His Return, it says:
"An then the sign of the Son of man will appear in heaven, an all the tribes of the earth will beat themselves in lamentation, and they will see the Son of man coming on the clouds of haven with power and great glory."
Of course, the JWs say "this means that only JWs would 'see' him, with the eye of understanding, not with their literal eyes." Even if you discount the sheer absurdity of such ridiculous reasoning, a good question is: why didn't the brothers predict this then? They said Jesus "returned invisibly in 1914", over a decade later! So they didn't "see" anything with the "eye of understanding when this event supposedly happened." DUUUUUUHHHH.
The Gentile Times is also another stupid doctrine. Discounting the 607 BCE doctrine, still doesn't make it any more believable. Luke 21 vs. 20 - 24 says "Furthermore, when you see Jerusalem surrounded by encamped armies, then know that the desolating of her has drawn near (this is obviously talking about the destruction of Jerusalem in 70 CE)...........and they will fall by the edge of the sword (still talking about the destruction in 70 CE) and Jerusalem will be trampled on by the nations, until the appointed times are fulfilled (suddenly, this is talking about 1914!)..........if they only had a brain................