[Michael The Disciple]

The gates of hades teaching is a false doctrine as taught by most Teachers and Churches. Jesus was talking about the fact that the grave (Hades) would not be able to hold the saints at the resurrection.

Paul wrote:

15:51 Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed,
15:52 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.
15:53 For this corruptible must put on incorruption, and this mortal must put on immortality.
15:54 So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory.
15:55 O death, where is thy sting? O grave, (HADES) where is thy victory?

Why does the Apostle teach that AT THE RESURRECTION the victory will be taken away from Hades?

Because HADES IS THE GRAVE!

At the resurrection when the Saints gain immortality then the saying of Yeshua that "the gates of Hades/Sheol will not prevail against the Church" will be fulfilled.