We've reached the conclusion of this series on the covenant as messenger theme in Doctrine & Covenants 45. Part 1 here. Part 2 here. Part 3 here. In this final installment, we'll look into the "day of righteousness" mentioned in verse 12:
11 Wherefore, hearken ye together and let me show unto you even my wisdom—the wisdom of him whom ye say is the God of Enoch, and his brethren,
12 Who were separated from the earth, and were received unto myself—a city reserved until a day of righteousness shall come—a day which was sought for by all holy men, and they found it not because of wickedness and abominations;
13 And confessed they were strangers and pilgrims on the earth;
14 But obtained a promise that they should find it and see it in their flesh.
Zion: "separated from the earth" and "received unto [Christ]"
This is an absolutely majestic description of what it means to be a part of Zion. It doesn't happen by chance, and it isn't enough to simply try to be a good person (the "covenant-consistent path" spoken of recently by Elder Christofferson). Rather, "the wisdom of ... the God of Enoch" would have us receive His messenger (the covenant) and come unto Him, whereby we simultaneously fulfill the measure of our creation and at the same time recognize our own sense of being out of place in a dark and dreary waste. Through this process it feels quite natural to advance to a new sphere of understanding, embracing more and more of God's commandments through covenant until we are separate from the fallen world and received into God's rest.
A "city reserved"
Zion is a connection point between heaven and earth, where "holy men" await the day of righteousness, when earth and heaven reunite. It is where we go (at least metaphorically) as we embrace Christ and thereby separate ourselves from the world. A place of gathering. A place that exists outside of time in some ways, from which the righteous (both those who are still alive and those who are dead) labor in the vineyard.
A detailed discussion of the events leading up to and at the day of righteousness falls outside of the scope of this post, but it's enough to say that every effort we've made to stay true to our covenants will be rewarded on that day.
The rest of this post is in Q&A format, outlining my understanding of righteousness, the day of righteousness, and some other related topics that didn't fit directly into the content above.
What is righteousness?
I highly recommend the series posted by Stisa on the topic (here, here and here) to get an overview of the ancient understanding of righteousness. In short, righteousness on the part of God is establishing the creation and the everlasting covenant and preparing the way for us to receive our divine inheritance. Righteousness on the part of humans is to live according to that covenant, to keep it and guard it as the most important aspect of our time in mortality.
Thus, righteousness can take many forms. Even the destruction of the wicked to answer the blood of the prophets crying up from the ground is a righteous act according to this understanding:
11 And because they did cast them all out, that there were none righteous among them, I did send down fire and destroy them, that their wickedness and abominations might be hid from before my face, that the blood of the prophets and the saints whom I sent among them might not cry unto me from the ground against them. (3 Nephi 9)
(It follows logically that receiving the prophets and hearkening to them is also righteous.)
Should we fear the "day of righteousness"?
If we live "righteously" (according to the purpose of the covenant/creation), we have no need to fear. We will be gathered For those in Zion, the day of righteousness will be a long-awaited restoration of all that feels right to them. They confess they are but "strangers and pilgrims" on the earth and wait patiently for the fulfillment of God's promise that they will see the day of righteousness in their flesh.
64 And there shall be mine abode, and it shall be Zion, which shall come forth out of all the creations which I have made; and for the space of a thousand years the earth shall rest. (Moses 7)
If we do not live righteously, we will experience God's righteousness at the day of Christ's return. To the extent that we have knowingly misused His creation, there will be a (righteous) restoration of harmony.
When is the "day of righteousness"?
If we understand the probationary time as "today" then I believe the scriptures make it clear that the day of righteousness is after that, so we can call it tomorrow (or the next phase of mortal existence), at the dawn of the Millennial Reign of Jesus Christ.