5 For [hoti] her [autos] sins [hamartia] have
reached [akoloutheo][kollao] unto [achri] heaven, [ouranos] and [kai] God [theos] hath remembered [mnemoneuo]
her [autos] iniquities. [adikema] KJV-Interlinear
5 for her
sins have piled up as high as heaven, and God has remembered her iniquities. NASB
Here is the tie between Babylon, and the sins of the last generation, that of the Tribulation.
Whereas, when Babylon was engaged in constructing the Tower of Babel, way back then, the objective was to reach heaven and join God on an equal basis.
That effort did not succeed.
But in the Tribulation, the sins of unbelievers and spiritually dysfunctional believers, will pile up and actually reach (symbolically) heaven, they will be so many.
The word for piled or reached, 'akoloutheo,' comes from the construction term, to glue together as in laying bricks. In construction, men will use mortar to seal bricks together in the construction process. This makes for a sound building when bricks are offset onto each other as the walls go up. But often times mortar is not used as the offsetting pattern in brick laying will serve as a seal unto itself. The Pyramids are a good example of this.
So, with no motive other than sinning for sins sake, the sins of the world will stack up one upon another and will do so until they are so numerous and beyond counting that the phrase of reaching heaven, describes the overwhelming sins that will exist in the world.
They will be so bound together, not loosely, that they will not topple over nor come apart even under their own weight. This describes the total adherence and commitment to sin that the world will have come to, and so bound up, that there will be no human solution for countering it. Only divine intervention will be able to stop the sin growth.
God remembers what He remembers. He is said to not remember the sins of believers, in forgiveness. This is a reference to confession (first in salvation and second in the spiritual life function).
But here, God remembers the sins of those who refused to believe. Believers receive forgiveness. Unbelievers do not.
Remember that the sins of the world were judged on the Cross. They were not forgiven. Forgiveness is the cleansing and washing process, which occurs subsequent to the payment for sins. The sins were first paid for, and then washed away.
When people believe in Christ, they are immediately washed, and thus forgiven. Subsequent to salvation, as believers when they sin, they must confess in order to receive the necessary additional washings in order to be forgiven for their indiscretions, and returned into fellowship.
Likewise, unbelievers had their sins judged, but they must believe in Christ in order to receive their first washing. Without belief, they are never washed and thus live in filth. That attitude is a rejection of Christ and His work on the Cross, and thus implies that the unbeliever can wash his own filth away, which he cannot. That means judgment is due. Judgment for unbelievers and discipline for believers who fail.
Therefore, God remembers, or brings or calls up the list of sins and attitudes of unbelief that exists behind them, back before the court of heaven, and issues judgments that are appropriate.