I have been rather enamored with the message of Joel lately. Joel is mistook as a prophet only concerned for people's salvation, and not just any people, but exclusively Israel. Merx calls Joel “fleshly and Jewishly particularistic." Such an interpretation could not be more wrong.
Joel proclaims the Day of the LORD. In this day, as Joel 1-4 proclaims, and other similar traditions agree (cf. Is. 44:1-5), creation is intimately involved.
Simkins (1991) says this: “This locust plague [in Joel 1-2] was unlike any plague which had ever previously invaded Judah, for according to Joel, it is to be understood as the chaotic enemy which poses a threat to Yahweh’s kingship and the stability of the created order.”
The locust enemy in Joel 1-2 that implies the beginning of the Day of the Lord (cf. Joel 1:15, "Alas the day!"), like the armies of the nations in Joel 3-4, all pose a threat to God's kingship and his beloved creation.
Isaiah 44:1-5 says, " “…For I will pour out water on the thirsty land, streams on the dry ground; I will pour out my spirit on you seed, my blessing on your offspring. They will sprout up like blades among the grass, like willows by flowing streams. This one says ‘I belong to Yahweh,’ and this on call out ‘In the name of Jacob,’ and this one writes on his hand ‘Belongs to Yahweh,’ and by the name of ‘Israel’ he is named.”
The categories of nature and humanity are mixed. The effect of such mixed categories conveys the meaning that there is regeneration of the natural world, and salvation of those in Israel that find their salvation in Yahweh. As Simkins observes, " Thus Joel proclaims that as the fertility of the land will be restored so also will the people be restored by the outpouring of Yahweh’s spirit. The salvation of nature and the salvation of the people are the same.”
So when Paul says, "For the creation waits with eager longing..." (Rom 8:19), and Jesus is said to "through him reconcile to himself all things, whether on either or in heaven" by the cross (Col 1:20), we can take it at its word. The regeneration of creation (THAT YOU AND I SCREWED UP) and the salvation of God's people is inaugurated in the Day of the Lord (NOW!).
Therefore when Wolff says so importantly: "When all salvation of Israel is the subject, the fate of the world of nations cannot be left out of the discussion, if one does not want to annul the prophetic tradition." I want to add, "and creation" to "the world of nations."