The great apostasy.

 However, the universal Christian Church could not have ceased for millennia in spite of all problems, because according to Christ, the forces of hell cannot prevail over it (Mt 16:18, Jude 24-25 cf. Eph 5:25-32). What is this Hades that will not prevail against the true church some underground realm of demons 

Acts ch.2:31NIV"31Seeing what was to come, he spoke of the resurrection of the Messiah, that he was not abandoned to the realm of the dead(Hades), nor did his body see decay."

So Hades is not a reference to superhuman wickedness but death, everyone bound for heaven must make a stop over in Hades/ Hell the true church refers to those heaven bound believers who remain faithful until death it's got nothing to to with these labels people like to wear

Revelation ch.2:26NIV"26To all who are victorious, who obey me to the very end,

To them I will give authority over all the nations."

Matthew ch.16:18NASB"And I also say to you that you are [m]Peter, and upon this [n]rock I will build My church; and the gates of Hades(the grave) will not overpower it. "

So the great apostasy did not stop the gathering of sanctified ones for the kingdom or represent a failure of Jesus promise at Matthew 16:18. 

Matthew ch.13:27-30NIV“ ‘An enemy did this,’ he replied.

“The servants asked him, ‘Do you want us to go and pull them up?’

“ ‘No,’ he answered, ‘because while you are pulling the weeds, you may uproot the wheat with them. Let both grow together until the harvest. At that time I will tell the harvesters: First collect the weeds and tie them in bundles to be burned; then gather the wheat and bring it into my barn.’ ”" all the apostasy means is that the few who were attempting to claw their way back to bible truth were scattered among the many who were Christians in name alone. But Jesus says that in the end times there would be a separating and a gathering of the fruit bearing wheat in one place and the fruitless weeds in another.

So who lied: Jesus or the Watchtower? The New Testament also writes about the need for constant defense of faith (Jude 3), not about a complete

JEHOVAH Does not need to have a majority on his side to defend his faith he is a majority unto himself

Judges 7:4ASV"And Jehovah said unto Gideon, The people that are with thee are too many for me to give the Midianites into their hand, lest Israel vaunt themselves against me, saying, Mine own hand hath saved me. "

So this is non point the basics were still present among a tiny persecuted minority and of course JEHOVAH Would consider the mitigation of their circumstance and overlook their shortcomings 

Acts ch.17:30ASV"The times of IGNORANCE therefore God overlooked; but NOW he commandeth men that they should all everywhere repent:"

JEHOVAH Has the power to raise the dead thus because some through no fault of their own die in ignorance it does not follow that such are eternally lost. 

Anonymous" disintegration and theological breakdown after the 1st century until the 1870s. The original text of 2Thess 2:3 is not "great apostasy", but "falling away" or "defection" (without any further detail), and this is when the Antichrist also appears, who sits in the temple of God, deifying himself etc. None of this has happened yet."

1John ch.2:18NIV"Dear children, this is the last hour; and as you have heard that the antichrist is coming, even now many antichrists have come. This is how we know it is the last hour.Dear children, this is the last hour; and as you have heard that the antichrist is coming, even now many antichrists have come. This is how we know it is the last hour."

The apostolic era was ending and John was putting the brothers on their guard as to what was to follow he said that they already heard that the antichrist was coming ,where would they have heard that. 

2Thessalonians ch.2:5,7NIV"Don’t you remember that when I was with you I used to tell you these things? 6And now you know what is holding him back, so that he may be revealed at the proper time. 7For the secret power of lawlessness is already at work; but the one who now holds it back will continue to do so till he is taken out of the way. 8A"

Paul is saying that the man of lawlessness/antichrist(it's a collective)was already present but there was someone( also a collective) holding him back but he is hinting that the one holding him back would soon be taken away. So at 1John ch.2:18 John is echoing Paul's words at 2Thessalonians ch.2:5-7 but the situation was more urgent at 2John because John was the last apostle and was at the end of his life.

We know that Satan operates in a very subtle manner we should not expect that the antichrist is going to declare himself the antichrist of course he is going to pretend to be a representative of Christ

Matthew ch.7:15NIV"“Watch out for false prophets. They come to you in sheep’s clothing, but inwardly they are ferocious wolves."

2Corinthians ch.11:14NIV"And no wonder, for Satan himself masquerades as an angel of light."

The anti Christ has come and as predicted has decieved the whole world.

Revelation ch.12:9KJV"And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the WHOLE world: he was cast out into the earth, and his angels were cast out with him. "

It's the mainstream that is in darkness truth is somewhere outside the mainstream Jesus gave the following advice in separating those who are in the light from those who are in the dark.

John ch.13:34,35KJV"34A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another. 35By this shall all men know that ye are my disciples, if ye have love one to another."

This love is not to be abrogated by any of the powers of the present age so you are not to murder your Christian brother regardless of which politician demands it.

The churches of Christendom have failed spectacularly to display this kind of love.

But by JEHOVAH'S Grace the brothers have proven ready to go to their deaths rather than violate Christ command. Thus fulfilling the sign.