5 And [kai] after [meta] that [tauta] I looked, [eido] and, [kai] behold, [idou] the temple [naos] of the
tabernacle [skene] of the testimony [marturion] in [en] heaven [ouranos] was opened: [anoigo] KJV-Interlinear
these things I looked, and the temple of the tabernacle of testimony in heaven
was opened, NASB
In an earlier vision, the throne room was opened allowing all to see inside. Now the tabernacle is opened to reveal the fact that what is now coming, is directly from God.
The tabernacle is now referring to Gods holiest of holies. This was the inner room in the earthly tabernacle, the Holy of Holies, into which only the High Priest was allowed to enter, and only twice on a single day on the Day of Atonement.
Inside that inner room, was the Ark, sometimes called the Ark of the Covenant. The covenant is Gods contract, Gods testimony to and with humanity.
And now that contract is going to be executed and completed, in the form of the most powerful and horrifying display of Gods judgment against sinful man and all evil, which has consumed the world.
Against it no one can hide, and no one can escape.
Having more than ample opportunity to turn away from evil, humanity will have chosen extreme wickedness, and when we finally get to verse eight, we will see that salvation will be closed. Not because it is intended to keep people out of heaven, but because all that will believe will already have believed and no more will believe in Christ, for the duration to the end of the Tribulation.
This closing will not occur early or even in the middle of the Tribulation, but near the end, there will come a time when that line will be crossed and all that remain of unbelievers, will not change in their attitude.
Today, we have seen unheard of disasters and atrocities in history, but when this series of events in the Tribulation begins, everything in past history will seem like childs play, as God unleashes the most complete execution of justice against evil, ever.
There can be no mistake. Life and happiness come from God, and judgment also comes from God, and from that there is no escape.