Did they preach something different than what they wrote?
I will assume you may be missed some of daniel1212's posts. He clearly pointed out in two of them (it was clear to me)there were no differences in the sermons of Paul and Peter in Acts. Nor are there differences with the epistles of Peter and Paul. Paul no doubt is the master theologian and Peter is no doubt the master pastor.
What has happened in these threads are posters are using sermons of Peter in Acts and comparing them to epistles of Paul. When you compare epistle to epistle there are no variations at all. Just as daniel1212 pointed out the same call to repentance in Acts by Peter was also called for by Paul in Acts.
I kindly ask to review daniel's last two posts because the questions you are asking me and then responding to are addressed in them.