Context: On the morning of Pentecost, the Spirit descends on the 120 gathered disciples in Jerusalem; they speak in the languages of the nations represented at the feast (Acts 2:5-11); the crowd reacts with amazement and mockery ("They are filled with new wine," 2:13). Peter stands with the Eleven and delivers the church's inaugural sermon. He begins by citing Joel 2:28-32 in full (Acts 2:17-21) as the interpretive key to what the crowd is witnessing, climaxing on Joel 2:32: "And it shall come to pass that everyone who calls upon the name of the Lord shall be saved (καὶ ἔσται πᾶς ὃς ἂν ἐπικαλέσηται τὸ ὄνομα κυρίου σωθήσεται)" (Acts 2:21). The sermon then pivots to Jesus: "Men of Israel, hear these words: Jesus of Nazareth, a man attested to you by God" (2:22), tracing His death, resurrection, and exaltation through the lens of Psalms 16 and 110. The climax identifies who the κύριος of Joel's promise is: "Let all the house of Israel therefore know for certain that God has made him both Lord and Christ (κύριον αὐτὸν καὶ χριστὸν ἐποίησεν ὁ θεός), this Jesus whom you crucified" (2:36). When the crowd, cut to the heart, asks what to do (2:37), Peter answers: "Repent and be baptized every one of you in the name of Jesus Christ (ἐπὶ τῷ ὀνόματι Ἰησοῦ Χριστοῦ) for the forgiveness of your sins" (2:38). The sermon's entire logic turns on the identification that the Name of Joel 2:32 — the saving Name — is the Name of Jesus.
Hebrew/Greek Key Terms:
OT-to-OT Development (how Peter reads the OT behind Acts 2:21): Peter's sermon treats three OT texts as convergent testimony to Jesus as the κύριος on whose Name salvation hangs.
The argumentative sequence is therefore: Joel 2:32 promises salvation to everyone who calls on the Name of κύριος; Psalm 16 shows that David's Holy One is risen; Psalm 110 shows that the risen-and-exalted figure is the second κύριος enthroned beside YHWH; this risen-enthroned-κύριος is "this Jesus whom you crucified" (2:36); therefore calling on the Name of κύριος in Joel's oracle means calling on Jesus. The logic is tight, textual, and canonically disciplined.
Connections:
Christological Connection: Acts 2:21 is the hinge at which the OT Name-trajectory lands in the apostolic proclamation. The connection operates primarily through Promise-Fulfillment, supported by Longitudinal Theme and Redemptive-Historical Progression.
By Promise-Fulfillment, Acts 2:21 quotes Joel 2:32 verbatim and the surrounding sermon identifies its fulfillment with specific textual arguments (Psalms 16 and 110) rather than bare assertion. This is the NT's most methodologically disciplined example of OT promise-to-NT-fulfillment reading: the text is cited exactly, the timing is identified ("in the last days," 2:17), the condition is preserved ("everyone who calls," 2:21), and the fulfillment is grounded in a prior textual argument that the Messianic κύριος stands at Yahweh's right hand (Psalm 110). Peter does not replace YHWH with Jesus; he identifies the risen-enthroned-Jesus as the κύριος of Joel's oracle on the warrant of David's "my Lord" at Yahweh's right hand. The κύριος of the Name-promise has been disclosed as Jesus.
By Longitudinal Theme, Acts 2:21 is the pastoral turning-point of the Name-trajectory: the point where the Name ceases to be an OT promise-in-wait and becomes a present saving invocation. Every stage of the trajectory converges here. The burning-bush disclosure ("I AM," Exodus 3:14) is the identity claim Peter presupposes when he calls Jesus κύριος. The Sinai Name-proclamation (Exodus 34:5-7 — merciful, gracious, forgiving iniquity, but not clearing the guilty) is the character-content Peter invokes when he preaches both forgiveness ("for the forgiveness of your sins," 2:38) and accountability ("this Jesus whom you crucified," 2:36) — both halves of the Name-character present and resolved at the cross. The Deuteronomic Name-dwelling (Deut 12:5, 11) is transcended: the Name now dwells not in a place but in a Person, and that Person is offered for naming in baptism (2:38). The prophetic universalizing of the Name (Malachi 1:11; Isaiah 52:6) begins to actualize as Jerusalem is filled with devout Jews "from every nation under heaven" (2:5) hearing the Name proclaimed in their own languages. The saving-Name-promise (Joel 2:32) is taken up by name and cited word-for-word. Acts 2:21 is where the Name-theology of the Hebrew Bible becomes the Name-theology of the church.
By Redemptive-Historical Progression, Acts 2:21 marks the Spirit-sealed inauguration of the last-days era: "in the last days" (ἐν ταῖς ἐσχάταις ἡμέραις, 2:17) the Spirit is poured out on all flesh, and the saving Name is offered to all who call. The promise is inaugurated but not consummated — the "great and magnificent day of the Lord" (2:20) with its cosmic signs awaits the parousia, and the universal knee-bowing of Philippians 2:10-11 awaits the end. Already/not-yet is built into Peter's sermon: the Spirit outpouring is already present (2:33 — "he has poured out this that you yourselves are seeing and hearing"), the saving invocation of the Name is already available (2:21, 38), but the cosmic signs and consummated Day remain future.
ANTI-DEFAULT CHECK: The primary method is Promise-Fulfillment — Acts 2:21 is a direct verbatim citation of Joel 2:32 interpreted as fulfilled in the Pentecost event, with a textually-disciplined argument (Psalms 16 and 110) showing that the κύριος of the promise is the risen-exalted Jesus. Longitudinal Theme is co-primary since this sermon is where the entire canonical Name-trajectory lands and becomes a present saving invocation. Redemptive-Historical Progression supports both. This is not typology: Acts 2:21 is not drawing a type-antitype relation; it is preaching that a prior verbal promise has come true, on the warrant of a prior textual identification (Psalm 110) of the Messianic κύριος. The identification of Jesus as the κύριος of Joel 2:32 is not escalation of a type but recognition of an identity (cf. TT 046 Divine Identity: Christ is Yahweh incarnate, not a greater figure replacing Him).
Connection Method(s): Promise-Fulfillment (primary) — Peter cites Joel 2:32 verbatim and the sermon's textual argument (Psalms 16 and 110) identifies the κύριος of the promise as Jesus, whose Name is now the saving Name offered in baptism. Longitudinal Theme (co-primary) — Acts 2:21 is the pastoral turning-point where the entire canonical Name-trajectory lands in present saving invocation. Redemptive-Historical Progression — marks the Spirit-sealed inauguration of the last-days era ("in the last days," 2:17). NT References — the sermon itself is a sustained NT use of OT Name-theology (Joel, Psalms 16 and 110, implicit Exodus 34) anchored to Jesus' resurrection and exaltation.
Trajectory Table: 105 - Name of God (Revelation of Divine Character)