Regarding Acts
Stevan Davies writes (Jesus the Healer, p. 174): "Luke wrote at least sixty years after Pentecost and perhaps closer to a century after that event. Scholarship on the subject presently vacillates between a late first century and an early to mid-second century date for Luke's writings."
Regarding Pilate, Robert Price writes about this in Deconstructing Jesus, p. 249:
Jesus' connection with the Roman governor Pilate on one end of his biography need be no more historical than his connection with the Roman governor Quirinius on the other. Even greater doubt is thrown on the matter by the parallel tradition, still extant but just barely, that Jesus was executed under Herod Antipas! The Gospel of Peter has Herod consult with Pilate but see to the execution himself. And, as Alfred Loisy noted long ago, Luke seems to have had access to a version of the Passion in which it was Herod who had Jesus killed, not Pilate. [The Origins of the New Testament, p. 192] This becomes evident when one examines the cumbersome and improbable sequence involving Jesus being tried before Pilate, then Herod Antipas, then Pilate again. No one has ever come up with a plausible reason for Pilate remanding Jesus to Antipas, as Luke has him do. Once Jesus gets to Herod's court, it is Herod's troops who mock him, not Pilate's as in the other gospels, implying that Luke was trying to harmonize the Markan Pilate-Passion with another set in Herod's court and had to choose between mockings. The most flagrant mark of indelicate editing is Herod's acquittal of Jesus--then sending him back to Pilate! It is clear Luke must have had one Passion story in front of him, Mark's, in which Pilate ordered Jesus' execution, and another, like that in the Gospel of Peter, in which it was Herod Antipas who condemned him. To use both, he had to change Herod's verdict from guilty to innocent (otherwise, as in the Gospel of Peter, he must have Herod send him to the cross). But instead of having Herod let Jesus go in peace, as an acquittal surely would demand, he has Herod send Jesus back to Pilate--for what? And if Pilate awaited Herod's verdict, why did he not let him go, too, since Herod had acquitted Jesus? Luke has too many cooks in the kitchen, and the stew is spoiled. But the key question is, if Jesus was known to have been crucified quite recently in dramatic public circumstances, at the behest either of Pilate or of Herod, how on earth could uncertainty over who killed him ever have arisen? If either Herod or Pilate had recently executed him, how could any belief about the involvement of the other have come about? But, on the other hand, if both were merely educated guesses as to who killed Jesus, we can easily see how the confusion arose.
Norman Perrin summarises four reasons that have lead critical scholarship to regard the pastorals as inauthentic (The New Testament: An Introduction, pp. 264-5):
Vocabulary.
While statistics are not always as meaningful as they may seem, of 848 words (excluding proper names) found in the Pastorals, 306 are not in the remainder of the Pauline corpus, even including the deutero-Pauline 2 Thessalonians, Colossians, and Ephesians. Of these 306 words, 175 do not occur elsewhere in the New Testament, while 211 are part of the general vocabulary of Christian writers of the second century. Indeed, the vocabulary of the Pastorals is closer to that of popular Hellenistic philosophy than it is to the vocabulary of Paul or the deutero-Pauline letters. Furthermore, the Pastorals use Pauline words ina non-Pauline sense:
dikaios in Paul means "righteous" and here means "upright";
pistis, "faith," has become "the body of Christian faith"; and so on.
Literary style. Paul writes a characteristically dynamic Greek, with dramatic arguments, emotional outbursts, and the introduction of real or imaginary opponents and partners in dialogue. The Pastorals are in a quiet meditative style, far more characteristic of Hebrews or 1 Peter, or even of literary Hellenistic Greek in general, than of the Corinthian correspondence or of Romans, to say nothing of Galatians.
The situation of the apostle implied in the letters. Paul's situation as envisaged in the Pastorals can in no way be fitted into any reconstruction of Paul's life and work as we know it from the other letters or can deduce it from the Acts of the Apostles. If Paul wrote these letters, then he must have been released from his first Roman imprisonment and have traveled in the West. But such meager tradition as we have seems to be more a deduction of what must have happened from his plans as detailed in Romans than a reflection of known historical reality.
The letters as reflecting the characteristics of emergent Catholocism.
The arguments presented above are forceful, but a last consideration is overwhelming, namely that, together with 2 Peter, the Pastorals are of all the texts in the New Testament the most distinctive representatives of the emphases of emergent Catholocism. The apostle Paul could no more have written the Pastorals than the apostle Peter could have written 2 Peter.
