2:28-29 After this, namely, after the deliverance from the northern invader just described, God promised to pour out His Spirit on all mankind without gender, age, class, or position distinction.29In Old Testament times God gave His Spirit only to select individuals (cf. Num. 11:24-29; 1 Sam. 10:10-11; 19:20-24), but in the future everyone (i.e., all believers) would prophesy and receive revelations from the Lord. Visions and dreams were God's customary ways of giving special revelations to people in Old Testament times (cf. Num. 12:6). Normally the absence of prophetic revelation indicated sin and divine judgment, but the presence of such revelation reflected divine blessing (cf. 1 Sam. 3:1). So a universal bestowal of the Spirit indicates a time of unprecedented divine blessing.
2:30-31 The Lord also promised awesome displays of celestial phenomena before this great and terrible day of the Lord arrived. Awe-inspiring miracles would occur in the sky as well as on the earth. The appearance of blood, fire, and columns of smoke suggests warfare, with God's hand at work behind the scenes (cf. Exod. 19:9, 16-18; Rev. 6:12-17). The sun would become dark and the moon would turn red. These are probably descriptions of how these heavenly bodies will look (language of appearance), not what will become of them, in view of other similar descriptions (e.g., vv. 10, 15; 3:15; Jer. 4:23-24; Ezek. 32:6-8; Amos 5:18-20; 8:9; Zeph. 1:15; Rev. 6:12-13). These signs will precede the great and awesome day of the Lord still future (cf. Matt. 24:29-31; Mark 13:24-27; Luke 21:25-28).
2:32 The promise continued that whoever would call on the name of Yahweh would be delivered. The day of the Lord described earlier in this chapter involved God judging the enemies of His people, and this eschatological day of the Lord also involves divine judgment. Therefore the deliverance in view must be from divine judgment (cf. Rom. 11:26). Specifically there will be people on Mt. Zion and in Jerusalem who escape, even among the survivors of previous distresses whom Yahweh has elected for deliverance (cf. Isa. 51:2; Zech. 13:8).
The Apostle Paul quoted this verse and applied it to spiritual salvation (Rom. 10:13). His usage does not fulfill what God promised here, namely, physical deliverance before the coming day of the Lord. Paul meant that just as God will deliver all who call on Him in that future day of the Lord, so He will deliver all who call on Him for salvation from sin. They will avoid the terrible day in which all unbelievers will be condemned by their Judge (Rev. 20:11-15).
The Apostle Peter also quoted this passage (vv. 28-32) in his Pentecost sermon (Acts 2:14-36). He said that what the people of Jerusalem were witnessing, which they mistook for drunkenness, was what Joel had spoken of (Acts 2:16-21; cf. Acts 10:45). Many interpreters believe that Peter meant that Joel's prophecy was fulfilled on the day of Pentecost. This can hardly be what he meant, however, because much of what Joel predicted in this passage did not occur on the day of Pentecost. The day of Pentecost was not the day of the Lord.
Another interpretation of Peter's meaning is that part of what Joel predicted was fulfilled on Pentecost, and the rest awaits fulfillment in the future day of the Lord. The problem with this view is that the promises of the outpouring of the Spirit and the other miracles are so intertwined that separating them by thousands of years seems unnatural. Moreover, Peter quoted the whole passage in Joel, not just the promise of the Spirit's outpouring.
A third possible interpretation is that Peter meant that what happened on Pentecost was similar to what Joel had prophesied God would do in the future day of the Lord. He drew a comparison and pointed out an analogy, but he did not claim fulfillment. This view sees the entire fulfillment of Joel's prophecy in the eschatological future. This view makes the most sense to me. The outpouring on the day of Pentecost was a foreview of what the Lord will do in the future (cf. Gal. 3:28).30
"Peter quoted this passage in Acts 2 because (a) it related to the outpouring of God's Spirit (2:4, 15-16), (b) it stressed his theme of repentance (2:21, 37-39), and (c) it fit with his understanding that the Jews were about to enter the Day of the Lord, leading up to the return of Israel's Messiah, Jesus (1:6-8; 2:36; 3:19-21)."31
The day of the Lord in view here begins with the Tribulation (cf. Dan. 9:24-27; Rev. 6-18), continues through the return of Christ and the Millennium (cf. Rev. 19-20), and culminates in the eternal state (cf. 2 Pet. 3:10-13; Rev. 21-22). The signs in view picture what the Book of Revelation describes further as occurring in the Tribulation, and the pouring out of the Spirit will occur in the Millennium. Then all believers will possess the Spirit and will have the ability to receive fresh revelations from the Lord. Forgiveness of sins and the indwelling of the Holy Spirit are two of four great blessings of the New Covenant (Jer. 31:31-34; Ezek. 36:24-30).
