5 But because of your stubbornness and your unrepentant heart, you are storing up wrath against yourself for the day of God’s wrath, when his righteous judgment will be revealed.

Read Romans 2:5 Using Other Translations

But after thy hardness and impenitent heart treasurest up unto thyself wrath against the day of wrath and revelation of the righteous judgment of God;
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.
But because you are stubborn and refuse to turn from your sin, you are storing up terrible punishment for yourself. For a day of anger is coming, when God’s righteous judgment will be revealed.