Henry Alford's Explanation of 2 Peter 1:1

2 Peter 1:1: Συμεὼν Πέτρος δοῦλος καὶ ἀπόστολος Ἰησοῦ Χριστοῦ τοῖς ἰσότιμον ἡμῖν λαχοῦσιν πίστιν ἐν δικαιοσύνῃ τοῦ Θεοῦ ἡμῶν καὶ Σωτῆρος Ἰησοῦ Χριστοῦ·

Next, as to the words τοῦ θεοῦ ἡμῶν καὶ σωτῆρος Ἰησοῦ χριστοῦ. Undoubtedly, as in Titus 2:13, in strict grammatical propriety, both θεοῦ and σωτῆρος would be predicates of Ἰησοῦ χριστοῦ. But here, as there, considerations interpose, which seem to remove the strict grammatical rendering out of the range of probable meaning. I have fully discussed the question in the note on that passage, to which I would refer the reader as my justification for interpreting here, as there, τοῦ θεοῦ ἡμῶν of the Father, and σωτῆρος Ἰησοῦ χριστοῦ of the Son. Here, there is the additional consideration in favour of this view, that the Two are distinguished most plainly in the next verse)

From Henry Alford - Greek Testament Critical Exegetical Commentary