The epistle of 1 Peter contains clues, some subtle and others overt, as to its intended audience. Let’s start at the very beginning:
Peter, an apostle of Jesus Christ,
To those who are elect exiles of the Dispersion in Pontus, Galatia, Cappadocia, Asia, and Bithynia, according to the foreknowledge of God the Father, in the sanctification of the Spirit, for obedience to Jesus Christ and for sprinkling with his blood… 1 Peter 1:1-2 (ESV)
Πέτρος ἀπόστολος Ἰησοῦ Χριστοῦ ἐκλεκτοῖς παρεπιδήμοις Διασπορᾶς Πόντου Γαλατίας Καππαδοκίας Ἀσίας καὶ Βιθυνίας κατὰ πρόγνωσιν Θεοῦ Πατρός ἐν ἁγιασμῷ Πνεύματος, εἰς ὑπακοὴν καὶ ῥαντισμὸν αἵματος Ἰησοῦ Χριστοῦ…
The Greek word here for Dispersion is Διασπορᾶς (Diasporas), and to Peter, the Diaspora can only pertain to one group: Jews. There is no such thing as a “Gentile Diaspora”, for the word calls back to the very first scattering and exile of the Jews by the Assyrians and later the Babylonians. That Peter goes on to describe them as sanctified in the Spirit and obedient to Jesus implies that his intended audience are Messianic Jews scattered around Asia Minor. We can read in the testimony of Paul that such a letter to this specific audience fits the character and calling of Peter:
…when they saw that I had been entrusted with the gospel to the uncircumcised, just as Peter had been entrusted with the gospel to the circumcised (for he who worked through Peter for his apostolic ministry to the circumcised worked also through me for mine to the Gentiles), and when James and Cephas and John, who seemed to be pillars, perceived the grace that was given to me, they gave the right hand of fellowship to Barnabas and me, that we should go to the Gentiles and they to the circumcised. Galatians 2:7-9 (ESV)
Continuing on through 1 Peter, what other internal evidence can we gather?
But you are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light. Once you were not a people, but now you are God’s people; once you had not received mercy, but now you have received mercy.
Beloved, I urge you as sojourners and exiles to abstain from the passions of the flesh, which wage war against your soul. Keep your conduct among the Gentiles honorable, so that when they speak against you as evildoers, they may see your good deeds and glorify God on the day of visitation. 1 Peter 2:9-12 (ESV)
Peter’s appeal to these individuals that they keep their conduct among the Gentiles honorable is further evidence that this letter is intended for Jewish believers. That the preceding paragraph is about those individuals being a chosen race and a holy nation is also indicative of the Jewish people from the perspective of one such as Peter. The Greek word used for Gentiles throughout 1 Peter is ἐθνῶν (ethnon) which simply means non-Jews, as it similarly translates the Hebrew goyim in the Septuagint.
Along with these specific examples are many more subtle examples of Jewish language that have not been contextualized for a non-Jewish audience – these examples include the language of “the spirits in prison”, the “Spirit of glory and of God” referring to the shekinah glory, or of “Babylon” being code for Rome. That Peter doesn’t expound or explain these indicates that he doesn’t need to – his primary audience would already be familiar with such technical language.
The internal textual evidence highly suggests that the primary audience of 1 Peter was to Jewish believers in Jesus who were living in Asia Minor. This in no way means the letter has no value to non-Jews, for we can reasonably assume that Gentile believers who were associating with Jewish believers were also recipients and readers of it. Certainly, the exhortations and promises given in the New Testament rightfully belong to all believers.
However, this should cause us to pause and consider the traditional practice of Gentile believers assuming upon ourselves full Jewish identity – when Peter uses the language of “elect”, our immediate desire is to take that on for ourselves, but is that valid given Peter’s own identity and calling to the Jews? This should also challenge theological strains of replacement/fulfillment that say the Church is the “new” holy nation and chosen people of God, rather than the fullness of those grafted into the existing body of Jewish believers, as Paul teaches in Romans 11. To do otherwise is to exegete outside of the boundary established by the Jewishness of Peter and his audience.