The operative verb in Acts 20:28 is περιποιέω (peripoieo) which occurs only three times in the NT: Luke 17:33, Acts 20:28, 1 Tim 3:13.
Thayer gives the following meaning:
περιποιέω, περιποιῶ: middle, present περιποιοῦμαι; 1 aorist
περιεποιησάμην; (see περί, III. 2); from Herodotus down; "to make to
remain over; to reserve, to leave or keep safe, lay by; middle to make
to remain for oneself," i.e.:
to preserve for oneself (the Sept. for הֶחֱיָה): τήν ψυχήν, life, Luke 17:33 T Tr WH (τάς ψυχάς, Xenophon, Cyril 4, 4, 10).
to get for oneself, purchase: τί, Acts 20:28 (Isaiah 43:21; δύναμιν, Thucydides 1, 9; Xenophon, mem. 2, 7, 3); τί ἐμαυτῷ, gain for
myself (Winer's Grammar, § 38, 6), 1 Timothy 3:13 (1 Macc. 6:44;
Xenophon, an. 5, 8, 17).
Only in Acts 20:28 is there a salvation meaning or 'overtone", essentially equivalent to buying or redeeming the people of God. As such, it is part of the "manumission" metaphor in the NT of Atonement metaphors (see appendix below).
Note carefully - the idea of Jesus buying our freedom by His death to free us from the slavery of sin, does NOT actually mean that He paid anybody anything - It is a metaphor and only used to convey the abstract idea of atonement as do all the other metaphors of atonement.
APPENDIX - Atonement Metaphors in the Bible
- Redemption, Ransom, or most correctly, Manumission: Two Greek words are translated “redeem” (“exagerazo” and “lutroo”) with almost exactly equivalent meanings. Both speak of Christ redeeming sinners as slaves (Luke 1:68, 24:21) by paying a ransom (Matt 20:28, Mark 10:45, 1 Tim 2:6, Heb 9:15), but, Scripture is silent about to whom the manumission fee was paid (it is only an analogue, metaphor or figure of speech!). 1 Cor 6:20, 7:23, Gal 3:13, 4:5, Titus 2:14, 1 Peter 1:18, Rev 5:9. This manumission idea emphasises God’s free gift of salvation because both Greek verbs were commonly used to buy freedom for a slave or hostage, without any contribution of the slave. Perhaps the most touching example of redemption is contained in the enacted parable of Hosea and Gomer – see Hosea 3:1-3.
The New Testament also presents several things from which the sinner needs freedom:
. o Freedom from the devil, Heb 2:14, 15
. o Freedom from death, 1 Cor 15:56, 57
. o Freedom from the power of sin that enslaves, Rom 6:22 (see also “Freedom”)
. o Freedom from the condemnation of the law, Rom 3:19-24, Gal 3:13, 4:5
- Christ’s robe of righteousness provided a covering to hide the sinner’s wretched state. Job 29:14, Ps 132:9, Isa 11:5, 59:17, 61:10, 64:6, Zech 3:4, 5, Matt 22:1-14 (wedding garment parable), Rev 3:4, 6:11, 7:9, 19:8. This robe is a counterpoint to the “filthy rags” of Isa 64:6 and Zech 3:4, and immediately and completely hides them.
- The Greek verb “aphiemi”, to forgive or give remission, means (literally) to send forth or send away. It is used of sins in Matt 9:2, 5, 6, 12:31, 32, 26:28, Mark 14:24, Acts 8:22, Rom 4:7, James 5:12, 1 John 1:9, 2:12, etc. That is, our sins are sent away or banished. See also Mark 3:29, Acts 5:31, 13:38, 26:18, Eph 1:7, Col 1:14. Again, Jesus accomplished this great work on the cross. See “Forgiveness”.
- Propitiation or expiation (Greek: “hilasterion”) denotes the act of appeasing a deity by sacrifice to incur divine favour (it is only an analogue, metaphor or figure of speech!). Thus, Jesus’ sacrifice is described as propitiation in Rom 3:25 and 1 John 2:2. These are direct references to the same word used in the Septuagint in Ex 25:17-22 (and repeated in Heb 9:5) where the “atonement cover” or “mercy seat” of the Ark of the Covenant is described. That is, the covering of the Ark provided both atonement and mercy at the same time! See also 1 Cor 5:7, 1 Pet 3:18. Thus, Jesus is correctly described as “the lamb of God who takes away the sin of the world.” (John 1:29, 36).
- Justify and Justification (Greek cognate root: “dike”) means to pronounce righteous or acquit and is obviously a legal term. Paul, in Romans, tells us that God has freely justified all sinners (Rom 3:23-27) and that this occurred while we were still sinners (Rom 5:5, 8, 9) by His death on the cross. This “declaring right” is clearly what God does and is His initiative and something that cannot be earned (Rom 3:20). In Gal 2:16 we are emphatically told that we are justified by trusting God and not by works of the law. See “Election” for more information. It is often used inter-changeably with “Credit”, see below.
- The Bible also uses the idea of Jesus’ death being a kind of penal substitutionary execution to satisfy the requirements of “the law”; thus, His death was an essential part of our salvation. Isa 53:5, 6, 11, 12, Matt 20:28, Rom 5:19, 2 Cor 5:21, Gal 1:4, 3:13, Heb 9:15. Again, the extent to which this is literally true is highly debated – is it only a metaphor to demonstrate God’s great love and grace? Or did Jesus’ death actually change something about God’s attitude to us (recall that Jesus is also God!) Obviously Jesus’ death did not change God’s mind because God gave His Son and God did not give something in order to change His own mind! Jesus death was to demonstrate His justice (Rom 3:22-28).
- In Rev 12:7-10 the process that leads to atonement is depicted as a war which Jesus wins. His victory obtains atonement for mankind (Col 2:15, 1 Peter 3:22). In this warfare, sinners are God’s enemies that He must capture in the war (Rom 5:10). This metaphor is extended for the Christian life (Eph 6:10-17, 1 Thess 5:8, 2 Cor 10:3-5, Isa 59:17) with “the armour of God”. See also Rev 19:11-21.
- The atonement is also presented as a kind of recapitulation: Jesus became the second Adam and succeeded where Adam failed. “For as in Adam all die, so in Christ all will be made alive” (1 Cor 15:22). Rom 5 discusses this idea at some length but the idea of sacrifice and the gift of salvation are never too far away even in this passage.
- “Credit”, “account”, “imputed”, or “reckoned” (Greek: logizomai) is a financial or accounting term used in the market place but was employed by Paul to denote the act of God in crediting Abraham (and sinners generally) as righteous when they trusted in God, apart from the works of the law, as a free gift. The idea is based upon the assumption that sin creates a debt to God which must be repaid (Col 2:13-15, Matt 6:12). Again, it is only an analogue, metaphor or figure of speech and so is not literally true. (Rom 4:3, 5, 6, 8, 9, 10, 11, 22, 23, 24, 2 Cor 5:19, Gal 3:6, James 2:23. See also Gen 15:6.) That is, the righteousness of God is “imputed” to the undeserving sinner, freely. Thus, God “cancels the debt” (Matt 18:21-35).
- “Gift” is used to convey the idea that atonement is absolutely free and the initiative of God. Rom 4:4, 5:15-17, 6:23, 2 Cor 9:14, 15, Eph 2:8, 3:7, Heb 6:4.
- Reconciliation describes the process of reuniting an estranged family member. It is predicated on two Biblical assumptions that (a) Jesus is our brother (Heb 2:11-13, Ps 22:22, Isa 8:17, 18, Matt 12:48, 49, John 20:17, Rom 8:29), and (b) sin separates us from Jesus our brother (Isa 59:2, Gal 5:4, Eph 2:12, Ps 22:1, Eze 14:5, Jer 6:8). Reconciliation is found in only a few places but they, again, emphasise that atonement is God’s initiative without any input from us. In 2 Cor 5:18, 19 we find that Christ reconciled the world to Himself by “not counting our sins against us”. Rom 5:10, 11 teaches that sinners were reconciled to God by Christ’s death. Further, a comparison with v9 shows that justification and reconciliation are used in parallel.
- Rescue (save): The Greek verb, “sozo” means literally to rescue or deliver from danger (Matt 8:25, Mark 13:20, Luke 23:35, John 12:27, 1 Tim 2:15, 2 Tim 4:18). Thus, when the New Testament discusses salvation, it is using the figure of someone in immanent mortal danger being rescued by a “rescuer” (Acts 2:47, 16:31, Rom 8:24, Eph 2:5, 8, 1 Tim 2:4, 2 Tim 19, Titus 3:5, etc). This a perfect figure of our relationship with Jesus who delivers us from the danger of sin (Phil 2:12) and eternal loss (Rom 13:11, 1 Thess 5:8, 9 2 Thess 2:13, Heb 1:14, 9:28, 1 Peter 1:5, 2 Peter 3:15, etc). See also Eph 6:17 where salvation is described as a helmet to protect from spiritual danger. This figure also emphasises that salvation must come from outside the person.
- The absolving of sin is sometimes represented as a “washing away” of sin, or “cleansing”. Lev 16:30, Num 19:9, Ps 51:2, 7, 10, Isa 4:4, Eze 36:25, Zech 13:1, 1 Cor 6:10, Eph 5:26, 1 John 1:7, 9. The practice of Baptism is built on this vivid metaphor and thus depicted as washing away of sin (Acts 22:16) as well as death to the old life and resurrection to a new life in Christ.