It's a scary thing in the eyes of Conventional Religion. Not so for Blake; for him it's Good News.
It's about Sin and Righteousness for them-- Good and Evil; (look at Matthew 25). Not so for Blake; there's no such thing. For him it's about Truth and Error. He acknowledged that good and evil exist; but it doesn't apply to people; you and I can be in a state of Satan, but that will never be a permanent state. ("Good and Evil are Qualities in Every Man"; Erdman 563)
For C.R. the Last Judgment is about the final end of the world. Not so for Blake! For him it's a personal thing that happens often in your life, and it's one-sided. Blake IMO was Universalist rather than narrowly Christian. Look at this verse from the Divine Image:
"And all must love the human form,
In heathen, Turk, or Jew.
Where Mercy, Love, and Pity dwell,
There God is dwelling too."
".......................What are all the Gifts of the
Spirit but Mental Gifts whenever any Individual Rejects Error &
Embraces Truth a Last Judgment passes upon that Individual"
(from Notes on Vision of the Last Judgment, Erdman 562)
You and I and Blake may very well pray for the Last Judgment.