The Greek text states,
ὃν δεῖ οὐρανὸν μὲν δέξασθαι ἄχρι χρόνων ἀποκαταστάσεως πάντων ὧν ἐλάλησεν ὁ θεὸς διὰ στόματος πάντων, ἁγίων αὐτοῦ προφητῶν ἀπ᾽ αἰῶνος
which I translate as,
whom Heaven must receive until the times of the ἀποκατάστασις of all things, which God spoke by the mouth of all His holy prophets from the most ancient time.
I did not translate ἀποκατάστασις since it is the word in question. BDAG and Thayer both define it as "restoration." Lidell-Scott-Jones defines it as "restoration, re-establishment."
The pronoun "which" following "all things..." does not refer to Jesus Christ, but "the times of the restitution of all things," as indicated by the case and number of the relative pronoun ὧν in agreement with χρόνων ἀποκαταστάσεως πάντων.
Firstly, the noun πάντων can be either masculine or neuter in gender. It can refer to all people (i.e., everyone), or all things (i.e., people, the world, etc.).
Secondly, while the noun ἀποκατάστασις only occurs once in the NT (in Acts 3:210), it is related to the verb ἀποκαθίστημι which occurs eight times.1
This verb is used in reference to:
- restoring the physical health and well-being of people (Matt. 12:13 cp. Mark 3:5, 8:25; Luke 6:10).
- restoring or re-establishing the kingom of Israel (Acts 1:6).
- restoring a man's presence to his brothers (Heb. 13:19)
But, more importantly, we should note that Jesus speaks of "the times of the restoration of all things" as having been spoken by the prophets from even the earliest of times. It is certainly true that the prophets spoke of the kingdom of Israel being re-established in the end of days,2 as well as the Messiah healing people.3 But, there's two scriptures in the NT that seem to shed more light on the usage of ἀποκατάστασις in Acts 3:21.
In Matt. 17:11 (cp. Mark 9:12), it is written,
And Jesus answered and said to them, "Indeed, Elijah shall come first and restore all things."
ὁ δὲ Ἰησοῦς ἀποκριθεὶς εἶπεν αὐτοῖς, Ἠλίας μὲν ἔρχεται πρῶτον καὶ ἀποκαταστήσει πάντα
This is the same thought we find in Acts 3:21.4 Here, we are told that Elijah would restore all things. If we examine the Tanakh, we'll find this idea in the Book of Malachi.
In Mal. 4:5-6, it is written,
Behold, I am sending you Eliyah the prophet before the coming of the great and dreadful day of Yahveh, and he shall turn the heart of the fathers towards the children, and the heart of the children towards their fathers, lest I come and smite the earth with a curse.
הִנֵּה אָנֹכִי שֹׁלֵחַ לָכֶם אֵת אֵלִיָּה הַנָּבִיא לִפְנֵי בּוֹא יוֹם יְהוָה הַגָּדוֹל וְהַנּוֹרָא. וְהֵשִׁיב לֵב אָבוֹת עַל בָּנִים וְלֵב בָּנִים עַל אֲבוֹתָם פֶּן אָבוֹא וְהִכֵּיתִי אֶת הָאָרֶץ חֵרֶם (MT)
καὶ ἰδοὺ ἐγὼ ἀποστέλλω ὑμῖν Ηλιαν τὸν Θεσβίτην πρὶν ἐλθεῖν ἡμέραν κυρίου τὴν μεγάλην καὶ ἐπιφανῆ ὃς ἀποκαταστήσει καρδίαν πατρὸς πρὸς υἱὸν καὶ καρδίαν ἀνθρώπου πρὸς τὸν πλησίον αὐτοῦ μὴ ἔλθω καὶ πατάξω τὴν γῆν ἄρδην (LXX)
The Hebrew verb וְהֵשִׁיב is translated in the LXX by the Greek verb ἀποκαταστήσει. This is a conjugation of the verb ἀποκαθίστημι which we discussed earlier. So, it was Elijah in the person of John the Baptist who would "restore" or "turn" the hearts of the sons to the fathers and vice versa. But, the people of Israel killed John the Baptist, just as they killed Jesus. Perhaps, then, Jesus is saying that Heaven receives him until the Holy Spirit completes the work which John and Jesus commenced.
Some may assume that Jesus is referring to the physical restoration of the world. But, Heinrich Meyer notes,
Accordingly the explanation of the universal renewal of the world unto a glory such as preceded the fall (παλιγγενεσία, Matthew 19:28; comp. Romans 8:18 ff.; 2 Peter 3:13) is excluded, seeing that that restoration of all things (πάντων) coincides with the Parousia (in opposition to de Wette, as well as many older expositors, who think on the resurrection and the judgment).
The correct interpretation must start from Malachi 4:6 as the historical seat of the expression, and from Matthew 17:11, where Christ Himself, taking it from Malachi, has made it His own. Accordingly the ἀποκατάστασις πάντων can only be the restoration of all moral relations to their original normal condition. Christ’s reception in heaven—this is the idea of the apostle—continues until the moral corruption of the people of God is removed, and the thorough moral renovation, the ethical restitutio in integrum, of all their relations shall have ensued. Then only is the exalted Christ sent from heaven to the people, and then only does there come for the latter the ἀνάψυξις from the presence of God, Acts 3:20.
What an incitement neither to neglect nor to defer repentance and conversion as the means to this ἀποκατάστασις πάντων! The mode in which this moral restitution must take place is, according to Acts 3:22, beyond doubt,—namely, by rendering obedience in all points to what the Messiah has during His earthly ministry spoken.
1 Matt. 12:13, 17:11; Mark 3:5, 8:25, 9:12; Luke 6:10; Acts 1:6; Hbr. 13:19
2 Isa. 53:4
3 Dan. 7:22, 7:26-27
4 In Acts 3:21, we find the noun ἀποκαταστάσεως followed by the genitive πάντων, meaning "restoration of all things." In Matt. 17:11, we find the verb ἀποκαταστήσει followed by the accusative πάντα, meaning "shall restore all things." The difference is simply a result of using a noun + noun and a verb + noun to express the thought.