One of the challenges of the letter to Ephesians is to understand how Paul could write a letter to a church where he had ministered for three and a half years, and yet in the letter it appears that he does not know the people to whom he is writing.
This explains the issues surrounding the inclusion of ἐν Ἐφέσῳ in 1:1 and the suggestion that the epistle is really a circular letter. But it does raise an interesting question about the translation of εἴ γε in 3:2 and 4:21.
“For this reason, I, Paul, the prisoner of Christ Jesus on behalf of you Gentiles— you have heard, haven’t you (εἴ γε ἠκούσατε), about the administration of God’s grace that he gave to me for you?” (3:1–2, CSB). The CSB at least indicates that Paul is not confident that his audience has heard, but gives the suggestion that they have. Other translations are a little more neutral, saying things like “assuming, by the way, that you know God gave me the special responsibility of extending his grace to you Gentiles” (NLT, also ESV).
We have the same situation in 4:21. “But that is not how you came to know Christ, assuming (εἴ γε) you heard about him and were taught by him, as the truth is in Jesus” (4:20–21, CSB).
What is surprising is the translation of NIV and NRSV, which use “surely.” “Surely you have heard about the administration of God’s grace” (3:2, NIV). “For surely you have heard about him and were taught in him, as truth is in Jesus” (4:21, NRSV). These translations are much more confident than the Greek allows about the audience’s knowledge of Paul’s ministry and the ethical message of the gospel.