Once, after a lecture, when I was autographing In Search of Paul, the purchaser asked me to write: "All we are asking is give Paul a chance." Exactly. (p. 146)Thirteen letters in the New Testament are attributed to Paul. Of those, there is scholarly consensus that seven are certainly by Paul. These seven are Romans, I and II Corinthians, Galatians, Philippians, I Thessalonians, and Philemon.
Three letters are probably not from Paul: II Thessalonians, Ephesians, and Colossians.
The last three: I and II Timothy and Titus are certainly not from Paul.
The reason for these judgments is the difference in style, tone, vocabulary, and content between the latter six and former seven letters. Those six post-Pauline letters were written in his name by later tradition but are actually anti-Pauline on certain subjects, such as slavery and patriarchy. We are dealing in other words, with a series of letters in which a radical Paul is transformed first into a liberal Paul and then into a conservative or reactionary Paul as we move from the seven certainly authentic letters through the three probably not authentic letters and finally into the three certainly not authentic letters. (p. 145)More on specifics later.