Over the last two weeks we have been studying 2 Peter 1. We saw that Peter made every effort to remind them of the things that were integral to the faith-the divine power of God in saving us, that power transforming our lives to look like Christ, and the invitation into the eternal kingdom. Peter says that he will use both personal testimony and scripture to make sure that they don't forget these things. But why, when Peter provides an example of personal testimony to the glory of God in v. 16-18 does he use the transfiguration? Why not his personal testimony to the resurrection, which would seem to be much more central to the gospel (1 Corinthians15:1-11) and an even greater moment of glorification?
The answer to this seems to be the context of what Peter is going to be talking about. There were false teachers who had begun infiltrating the churches that Peter is writing to. These false teachers, among other things, seemed to be teaching that the delay in Jesus' return was an indication that He was not returning-or, even more likely, that Jesus wasn't who He claimed to be.
Peter chooses the transfiguration over the resurrection as his personal testimony of the glory of God because the transfiguration is a foreshadowing of the glory that Jesus will have in His millennial kingdom. Additionally, it was a strong statement that Jesus superseded both the Law (Moses) and the prophets (Elijah).
Some have used this to suggest that Peter and Paul are at odds with each other. Paul, in his 1 Corinthians 15 passage is laying out a gospel that is spiritual/resurrection oriented. Peter in this passage is laying out a kingdom-oriented gospel.
However, rather than Peter and Paul being at odds with each other regarding their Christology, we see that actually Peter and Paul are on the same page. They both speak of the importance of believers proclaiming our personal testimony to witnessing the glory of God in Jesus. Their difference in events has more to do with the context of the circumstances that they are writing about rather than a difference in their theologies.