I have just listened to Bart Ehrman in a discussion with Darryl Bock on the Unbelievable? radio show. Ehrman was arguing that Peter didn't write the letters ascribed to him because he wouldn't have known Greek and even if he did, he couldn't have written a literary document in that language.
Now, there are a couple of things to be said here. Firstly, how does he know specifically what Peter could or couldn't do? I would imagine that a place known as "Galilee of the Gentiles" (see here) would have been a bilingual area having plenty of Greek speakers. As regards writing, perhaps Peter was taught in these things and that was why he could run a fishing business (with his partners, James and John, having hired servants) and trade with people of different nationalities in Galilee. Perhaps that was one reason for his selection as an apostle and a reason for his prominence in the early church. Is it likely Peter would have had such prominence and influence in the early church if he couldn't even speak or write in Greek?
If Ehrman's view is correct, would the early believers not have thought it a bit odd to have a letter from someone whom they knew couldn't speak or write in Greek? Would the forger not have known that Peter was a non-Greek-speaking illiterate? Are we to suppose that we are better placed here in the 21st century than the "Church Fathers" of the first and second centuries to know what was possible for a Galilean fisherman? All the testimony from the early church is that Peter did write the letters ascribed to him, and there is nothing from that time to suggest he didn't, (Clement of Rome, AD 96, quotes from 1 Peter 5; Eusebius tells us that Papias, c. AD 60-130 made use of Peter's writings; Polycarp, martyred in the middle of the second century, quoted extensively from 1 Peter; Iranaeus and Tertullian, at the end of the second century, identify Peter as the author of 1 Peter, and in the middle of the second century Clement of Alexandria wrote a commentary on the epistle. Another thing is that the existence of 2 Peter is an early indication of how widespread and deeply it was believed that 1 Peter was written by Peter, that is, even if 2 Peter were a forgery (which I don't believe for a moment), the fact that the writer refers to the earlier epistle shows that 1 Peter was taken to be written by Peter.
In addition, there are many incidental, under the surface, allusions to things that happened during Peter's time with the Lord (e.g. 1 Peter 5 v 2 with John 21 v 15-16; 1 Peter 5 v 5 with John 13 v 4; 1 Peter 5 v 8-10 with Luke 22 v 31-32). Because these are under the surface and not explicitly highlighted supports the view that these were the memories of an eyewitness coming out in his writing.
Another thing, I don't understand why Bart dismissed the explicit statement that the actual writing was done by Silvanus (i.e. Silas), see 1 Peter 5 v 12. Even if Peter struggled with the writing (again, I don't believe he did), he could have and surely would have found someone to do it for him.
But there is a more foundational issue: the Christian position is that these writers were not writing unaided, but were borne along by the Holy Spirit (2 Peter 1 v 21). The Holy Spirit would give His help and guidance in what Peter wrote. Another thing, Peter was an apostle possessed with the gift of tongues - presumably if he could speak in languages he had never learnt (which is what the Scriptural gift of tongues was) then he would have been able to communicate that to a penman to write it, (although we don't need to appeal to the miraculous use of tongues, but my point is that even if he couldn't speak Greek prior to Pentecost, he could do it in the power of the Spirit after).
It was interesting to see how Ehrman brought up a couple of things as contradictions that are not contradictions at all if you just look at the context. For example, he says that Ephesians contradicts 1 Corinthians 15 because Ephesians says we have been raised up, but 1 Corinthians 15 says it hasn't happened yet, but of course, Ephesians is talking about spiritual quickening, while 1 Corinthians 15 is talking about physical, bodily quickening. This is evident because the death Ephesians speaks of is spiritual death, but the death 1 Corinthians 15 is talking about is physical death. And it should be observed that Ephesians does talk about the future glorification of the body, in chapter 4 v 30 he speaks about the day of redemption in which the body will be freed from the effects of the curse and handicap of carnality and mortality.
Again, a dispensational, pretribulation rapture view would have sorted out the "contradiction" between 1 and 2 Thessalonians, i.e. the passages that speak about the Lord's return as being imminent are in reference to the first stage of His coming in which Christians will be caught away to be with Him, and the passages that speak of signs preceding His coming have to do with that second stage in which He comes to earth, (and this view sorts out every perceived contradiction people see in end-times teachings).
God, in His power and providence, has ensured that we have His completed revelation, and what Peter's epistles say comes with all the authority of God, so we know that there is awful judgment for the one who rejects the truth (2 Peter 2 v 17; 1 Peter 4 v 17), yet God has made provision for us to be brought to Him by means of the sacrifice of Christ (1 Peter 3 v 18), and in longsuffering waits for sinners to come to repentance (2 Peter 3 v 9), and by repenting and putting your faith in Christ your soul will be saved from the penalty of sin and your heart will be purified from the defilement of sin (1 Peter 1 v 9, 22. That's Peter's message, but more importantly, it's God's message!