By which also he went and preached unto the spirits in prison. (1 Pet 3:19)
Sometimes, critics of the Latter-day Saint interpretation of 1 Pet 3:19-21 will argue that the verb used in v. 19 (κηρυσσω) does not mean "to preach" but instead means "to proclaim," and that Peter is stating that Christ proclaimed a message of condemnation to those in the spirit world.
Firstly, many English translations render this verb as "preach" and not simply just "proclaim," such as the KJV; NJB; ASV; DR; ERV; Geneva; NLT; RSV; Tyndale.
Secondly, κηρυσσω is often used by the New Testament authors for the preaching of the Gospel of the Kingdom; it strains credulity to think that this was Christ and the Apostles merely proclaiming the gospel and the future Kingdom without a goal towards seeking converts thereto; note the following examples:
From that time Jesus began to preach (κηρυσσω), and to say, Repent: for the kingdom of heaven is at hand. (Matt 4:17)
And Jesus went about all Galilee, teaching in their synagogues, and preaching (κηρυσσω) the gospel of the kingdom, and healing all manner of sickness and all manner of disease among the people. (Matt 4:23)
And Jesus went about all the cities and villages, teaching in their synagogues, and preaching (κηρυσσω) the gospel of the kingdom, and healing every sickness and every disease among the people. (Matt 9:35)
As you go, proclaim (κηρυσσω) the good news, 'The kingdom of heaven has come near.' (Matt 10:7)
What I tell you in darkness, that speak ye in light: and what ye hear in the ear that preach (κηρυσσω) ye upon the housetops. (Matt 10:27)
And it came to pass, when Jesus had made an end of commanding his twelve disciples, he departed thence to teach and preach (κηρυσσω) in their cities. (Matt 11:1)
And this gospel of the kingdom shall be preached (κηρυσσω) in all the world for a witness unto all nations; and then shall the end come. (Matt 24:14)
Verily I say unto you, Wheresoever this gospel shall be preached (κηρυσσω) in the whole world, there shall also this, that this woman hath done, be told for a memorial of her. (Matt 26:13)
Then Philip went down to the city of Samaria, and preached (κηρυσσω) Christ unto them. (Acts 8:5)
Then certain of the vagabond Jews, exorcists, took upon them to call over them which had evil spirits the name of the Lord Jesus, saying, We adjure you by Jesus whom Paul preacheth (κηρυσσω) (Acts 19:13)
But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach (κηρυσσω). (Rom 10:8)
Preach (κηρυσσω) the word; be instant in season, out of season; reprove, rebuke, exhort with all longsuffering and doctrine. (2 Tim 4:2)
Thirdly, scholarly lexicons support the view that κηρυσσω is more than just “to proclaim”; notice the following from (1) BDAG and (2) Louw-Nida as two representative examples:
4232 κηρύσσω
• κηρύσσω impf. ἐκήρυσσον; fut. κηρύξω; 1 aor. ἐκήρυξα, inf. κηρύξαι (also κηρῦξαι, so Tdf.); on the accent s. B-D-F §13; PKatz-Walters, The Text of the Septuagint, Cambridge ’73, 97); pf. inf. κεκηρυχέναι (Just., D. 49, 2). Pass.: 1 fut. κηρυχθήσομαι; 1 aor. ἐκηρύχθην; pf. κεκήρυγμαι (Just.) (s. two prec. entries; Hom.+; ins, pap, LXX; PsSol 11:1; TestLevi 2:10; GrBar 16:4 [-ττ-]; Philo, Joseph.; loanw. in rabb.; apolog. exc. Ar.).
1. to make an official announcement, announce, make known, by an official herald or one who functions as such (Maximus Tyr. 1, 6c κηρύττομαι=I am being announced by the herald) MPol 12:1 of the pro-consul, who announced three times that Pol. had confessed to being a Christian.—Rv 5:2.
2. to make public declarations, proclaim aloud
a. gener. speak of, mention publicly w. acc. κ. πολλὰ τὸν λόγον spread the story widely Mk 1:45. The hospitality of the Cor. church 1 Cl 1:2. W. indir. discourse foll. Mk 5:20; Lk 8:39. Abs. Mk 7:36.—S. below 2bβ.
b. of proclamation that is divine in origin or relates to divinity (Epict. 3, 13, 12 of the peace of wise men, which does not originate w. the emperor, but is ὑπὸ τοῦ θεοῦ κεκηρυγμένη διὰ τ. λόγου. Of the [objectionable] myths of the Greeks ταῦτα … οἱ … συγγραφεῖς καὶ ποιηταὶ κ. Theoph. Ant. 1, 9 [p. 78, 13]).
α. of the proclamation or oracles of the older prophets (Jo 2:1; 4:9; Jon 1:2; 3:2; Jos., Ant. 10, 117; Just., A I, 54, 2) Ἰωνᾶς Νινευΐταις καταστροφὴν ἐκήρυξεν 1 Cl 7:7 (Jonah as Jos., Ant. 9, 214; Just., D. 107, 2f; Orig., C. Cels. 7, 57, 3); cp. vs. 6; 9:4 (Noah as SibOr 1, 128); 17:1 (Elijah and Elisha, also Ezekiel); B 6:13 (ὁ προφήτης). προφήτας [ἐξ]έπεμψεν κ. … χριστὸν Ἰησοῦν AcPl Ha 8, 17//Ox 1602, 19-21//BMM recto 21f. Ἰωνᾶς … [ἵνα] εἰς Νεινεύη μὴ κηρύξῃ AcPl Cor 2:29. οἵτινες τὴν ἀπλανῆ θεοσέβειαν ἐκήρυσσον who proclaimed the inerrant way of revering God 2:10.
β. of contemporary proclaimers (POxy 1381, 35; 144 [II AD]: of the great deeds of the gods; Herm. Wr. 1, 27; 4, 4.—Philo, Agr. 112 κήρυξον κήρυγμα τοιοῦτον. S. κῆρυξ 2.—Also of false prophets: Jos., Bell. 6, 285), of Mosaic tradition and its publication, the preaching of John the Baptist, and propagation of the Christian message in the widest sense: Μωϋσῆν preach (=advance the cause of) Moses i.e. the keeping of the law Ac 15:21. περιτομήν proclaim circumcision i.e. the necessity of it Gal 5:11 (here and 2a the mng. praise publicly is also prob.: X., Cyr. 8, 4, 4; Polyb. 30, 29, 6). κ. μὴ κλέπτειν inveigh against stealing (=preach: No stealing!) Ro 2:21.—κ. τι proclaim, someth. (ἕνα θεὸν παντοκράτορα καὶ ἕνα μονογενῆ Χριστὸν Ἰησοῦν κ. Iren. 1, 9, 2 [Harv. I 82, 5]; τὸν ἄγνωστον πατέρα 1, 26, 1 [Harv. I 211, 11]; Hippol., Ref. 1, Prol. 7; Did., Gen. 183, 6; 209, 13) Mt 10:27; pass. Lk 12:3. ἐνιαυτὸν κυρίου δεκτόν 4:19 (cp. Is 61:1f). τὸν λόγον 2 Ti 4:2. τὸ ῥῆμα τῆς πίστεως the message of faith Ro 10:8. τὴν βασιλείαν τοῦ θεοῦ Lk 8:1; 9:2; cp. Ac 20:25; 28:31. τὸ εὐαγγέλιον Mk 16:15; Ac 1:2 D; Gal 2:2; B 5:9; GMary Ox 3525, 28; 32. τὸ εὐ. τ. βασιλείας Mt 4:23; 9:35 (cp. τὸν περὶ τοῦ θεοῦ καὶ τῆς βασιλείας αὐτοῦ λόγον Orig., C. Cels. 3, 40, 20); τὸ ὄνομα τοῦ υἱοῦ τοῦ θεοῦ Hs 9, 16, 5. W. dat. of pers. (Hippol., Ref. 5, 26, 30) 1 Cor 9:27 (on the topic of dreaded failure s. APapathomas, NTS 43, ’97, 240); 1 Pt 3:19 (CCranfield, ET 69, ’57/58, 369-72; see lit. s.v. πνεῦμα 4c); GPt 10:41. εἰς τὰς συναγωγάς in the synagogues Mk 1:39; Lk 4:44. τινί τι someth. to someone (of Jesus κ. μετάνοιαν ὅλῳ τῷ κόσμῳ Orig., C. Cels. 7, 57, 4; τὸ κηρῦξαι αὐτοῖς τὸ εὐαγγέλιον Did., Gen. 53, 13) 4:18; B 14:9 (both Is 61:1). τὶ εἴς τινα someth. to someone τὸ εὐαγγέλιον εἰς ὑμᾶς 1 Th 2:9. εἰς ὅλον τὸν κόσμον Hs 9, 25, 2. Pass. εἰς τὰ ἔθνη Mk 13:10 (DBosch, Die Heidenmission in der Zukunftsschau Jesu ’59, 159-71); κ. τὸ εὐ. Mt 24:14; 26:13; Mk 14:9; Col 1:23.—βάπτισμα proclaim baptism i.e. the necessity of it Mk 1:4; Lk 3:3; Ac 10:37. ἐκηρύχθη ἡ σφραγὶς αὕτη H 9, 16, 4. κηρυχθῆναι … μετάνοιαν εἰς ἄφεσιν ἁμαρτιῶν repentance for the forgiveness of sins Lk 24:47. ἵνα μετανοῶσιν Mk 6:12. [ἀνδρῶν τῶν] κηρυσσόντων, ἵνα μετανοῆται (read: -ῆτε) AcPl Ha 1, 17.—τινά (τινι) someone (to someone) Χριστόν Ac 8:5; cp. 1 Cor 1:23; Phil 1:15. Ἰησοῦν Ac 19:13; 2 Cor 11:4. οὐχ ἑαυτοὺς κηρύσσομεν ἀλλὰ Χριστὸν Ἰησοῦν κύριον we do not publicize ourselves, but Christ Jesus as Lord 4:5. Pass. ὃς (Χριστός) … ἐκηρύχθη 1 Ti 3:16; cp. Hs 8, 3, 2; 9, 17, 1; Dg 11:3. διά τινος through someone (cp. Epict. 3, 13, 12) Χρ. ᾽Ι ὁ ἐν ὑμῖν δι᾽ ἡμῶν κηρυχθείς 2 Cor 1:19. W. an addition that indicates the content of the proclamation, introduced by ὅτι (cp. Epict. 4, 5, 24): κ. w. acc. and ὅτι foll. Mk 1:14 v.l.; Ac 9:20; pass. Χρ. κηρύσσεται ὅτι ἐκ νεκρῶν ἐγήγερται Christ is proclaimed as having risen fr. the dead 1 Cor 15:12. κ. τινί, ὅτι Ac 10:42; οὕτως κ. 1 Cor 15:11. The content of the proclamation is introduced by λέγων Mt 3:1f; 10:7; Mk 1:7; cp. vs. 14; IPhld 7:2. Beside λέγειν w. direct discourse (Epict. 4, 6, 23) Mt 4:17. Abs. Mt 11:1; Mk 1:38; 3:14; 16:20; Ro 10:15; 1 Cl 42:4; B 5:8 (Jesus’ proclamation defined as teaching and the performance of wonders and signs); 8:3. κηρύσσων a proclaimer Ro 10:14.—S. lit. under κήρυγμα; also MGrumm, translating kerusso and Related Verbs: BT 21, ’70, 176-79.—B. 1478. DELG s.v. κῆρυξ. M-M. EDNT. TW. Sv.
33.207 κηρύσσω ; διαγγέλλω: to announce extensively and publicly - 'to proclaim, to tell.' κηρύσσω: ἤρξατο κηρύσσειν ἐν τῇ Δεκαπόλει ὅσα ἐποίησεν αὐτῷ ὁ Ἰησοῦς 'he began to proclaim in Decapolis all that Jesus had done for him' Mk 5.20. διαγγέλλω: σὺ δὲ ἀπελθὼν διάγγελλε τὴν βασιλείαν τοῦ θεοῦ 'you go and proclaim the kingdom of God' Lk 9.60.
Fourthly, there is a strong body of scholarship supporting the view that Christ preached, not simply proclaimed, to the spirits in 1 Pet 3:19-21. For two representative examples:
Archbishop Hilarion Alfeyen, Christ the Conqueror of Hell: The Descent into Hades from an Orthodox Perspective
Jeffrey A. Trumbower, Rescue for the Dead: The Posthumous Salvation of non-Christians in Early Christianity
The LDS interpretation of this pericope is on sound footing; the critics harping about the meaning of κηρυσσω is question-begging as it can mean “to proclaim,” “to preach,” and even both per the context—critics will have to show us that κηρυσσω does not carry the connotation of “to preach” before making any dogmatic assertion.