Yesterday, for the first time, I sang a funeral mass according to the pre-Vatican II “Tridentine” form of the Roman rite, and it made me realize how we, 21st century people, could easily misunderstand the medieval concept of God’s judgment and of “wrath”.
This funeral mass is also called “Requiem mass”, and its text was echoed by the many musical versions offered by composers over the centuries. Two famous examples are below:

Dies Irae from Verdi’s “Requiem Mass” (1874)

Dies Irae from Mozart’s “Requiem Mass” (1791)
https://www.youtube.com/watch?v=0T7eMctuJLQ

Until a recent past, I identified this music to “God’s wrath”, and I am probably not alone in having thought so. Singing the “original” Dies Irae, the one that entered the funeral mass in medieval times made me realize how wrong I was.

First, God has nothing to do with that wrath. The text does not say “Ira Dei” (God’s wrath), but “Dies Irae” (day of wrath). Whose wrath is it, then? The second verse tells us that “David and Sibylla” foretold us about it. I have not read Sybilla, but we consider the psalms to be David’s writings, and in the psalms, God is the protector, not the angry one. In Psalm 109 for example, the anger is clearly human, on both sides. Death and judgment ensue from wrath, but the psalmist is not denying that the anger is his.
In singing the “medieval” Dies Irae yesterday, the music given me for this text was introspective, begging, sad and full of contrition. But it was not angry at all. By the time I was singing the last verses, starting with “Lacrimosa dies illa, qua resurget ex favilla” (Mournful day! That day of sighs, when from dust shall man arise), I was holding back tears, in awe, but still hopeful. This is a funeral mass after all: the casket is present, and the role of the cantor (or choir) is to humbly pray God for the salvation of the soul of the deceased. While singing, I did feel on the “edge” between this world and the next. Exactly where sacramental music is supposed to take me.

So singing the Dies Irae has nothing to do with acting out God’s anger. I say this with all due respect to Mr. Mozart and Mr. Verdi. They had no idea their outstanding work was going to become the soundtrack for a so-called “God’s anger” to our generations. As a comparison, here is a recording of the medieval (and liturgical) Dies Irae I sang yesterday at mass:
https://www.youtube.com/watch?v=dsn9LWh230k

What I felt while singing it is that God is all-powerful, beyond our understanding, but also just and merciful. And I will die someday. The liturgical music makes clear that the “wrath” mentioned in the text is not God’s. I hope this is as helpful to you as it is to me.