“But because of your hard and impenitent heart you are storing up wrath for yourself on the day of wrath when God’s righteous judgment will be revealed.” -Romans 2:5
This passage is remarkable in that it emulates the similar process of Romans one where the outwardly unrighteous are continuously hardened by their further rejection of God.
While the outwardly wicked of chapter 1, having turned from God and are being given up by God continue the cycle by hardening themselves even more and are given over to the lusts of their minds until they are utterly destroyed, these outwardly religious, these self-righteous, these hypocrites are similarly accumulating to themselves the indignation of God, but in a unique manner.
In the same manner he gives up the unrighteous to do what their depraved minds desire to do, he gives to these gifts upon gifts, blessings upon blessings, which they continually enjoy, not to their improvement as they were intended, but to the increase of their condemnation.
The gifts of God only harden the hearts of the self-righteous in the same way the selfish desires of the unrighteous harden theirs. Both are literally storing up the evidence against themselves for the unspeakable day of judgment when the fullness of God’s righteous judgment will be revealed.
“A day of wrath is that day, a day of distress and anguish, a day of ruin and devastation, a day of darkness and gloom, a day of clouds and thick darkness,” -Zephaniah 1:15
“Woe to you who desire the day of the Lord! Why would you have the day of the Lord? It is darkness, and not light,” -Amos 5:18
As John Calvin soberly noted, “Let us then take heed, lest by unlawful use of blessings we lay up for ourselves this cursed treasure.”