Now John shifts his focus to the confidence that Christians can have in Christ. Having seen the dangers of false teaching, it remains now to see how we are to live.
v28. John begins by urging his children to “continue in [Jesus].” These types of exhortations have appeared and will continue to appear all throughout this book (cf. 1:12-14; 2:20, 24, 27, etc.). Since a person cannot “continue in” something they are not already in, this is yet another reason to remember that John is writing to believers–to people who are already in Christ.
The reason they are to continue in Christ is so that “when He appears we may be confident and unashamed before Him.” It is unclear if the “we” here refers to the apostolic community or to the general church. If the community (as in chapter 1), then John is saying that if his children in the faith falter, he himself will suffer loss, much as any father is embarrassed when his children get into serious trouble. This is actually my preferred view, because I tend to think this ties back into the overall purpose of the book, which is how to have fellowship both with Christ and with one another. After all, if these believers do continue in Christ, then John can be confident, which would only enhance their fellowship with him.
If, on the other hand, the “we” refers to Christians generally, the message is simply that if we do not remain or abide in Christ, then we will be embarrassed when He returns. In fact, whichever view of “we” we take, this ends up being the bottom line. If we want to be confident and hear “Well done my good and fail servant,” we must “continue in Him.” Such praise from Jesus is simply not guaranteed to all believers, even if their eternal salvation from Hell is.