Wikipedia makes the claim that 2 Peter might not have been written by Peter. Any evidence to this? Is there evidence that points to Peter actually being the author?
I believe that Peter wrote this book because it was the tradition of the church from a very early date that it was in fact written by Peter. Bottom line, those in the best position to know–those who knew Peter and those who lived within one or two generations of his life said it was written by Peter. I do not believe any modern day scholar is in a better position than the church in the first and second century to decide the authorship. They decided the letter is apostolic. The letter itself claims to be written by Peter. Some argue that this claim was added to the letter by a later editor in order to strengthen the tradition, but there is no direct evidence supporting this contention. The style and subject are so similar to 1st Peter that I assume either both were written by Peter or neither was written by Peter. All the evidence taken together makes a strong case that Peter wrote the book.
Having said that, the fact is that many modern scholars are of the opinion that Peter did not write these books and even in the early church the majority said Peter did write it, but some were not sure. Those who deny Petrine authorship today generally do so because of its theological content rather than because of any hard evidence one way or another whether Peter wrote it. As a rule we cannot "prove" that any Bible book was written by the traditional author. We do not have the original manuscript, and even if we did, it is not clear how we could ever prove, two thousand years after the fact, who wrote it.
In the end, the overall evidence that the Bible is inspired by God is really the most important reason to have confidence in the Scripture. The question for the Christian believer is whether the book of 2nd Peter is inspired by God. The question of inspiration is more fundamental than the question of authorship. I believe the content speaks for itself. This is an amazing book. I am convinced, both by the evidence but also because of my belief in the faithfulness of God–that He carefully saw to the completion of the Scripture, that this book is inspired by God. Did Peter write the book? I believe so, but I will admit I might be wrong. I cannot rule out the possibility that the early church fathers believed so and for that reason addded the first verse. All I can say is that in my opinion, based on what I have already said, I believe this is most likely not true. What I am quite sure of is that the book is inspired by God, and in the end, this is what is most important.