The Acts Of Peter And Paul
The apostle Peter was a prevalent figure through the "Gospel" books of Matthew, Mark, Luke and John, not because Peter was the "leader" of the apostles or the Christian Church (only Christ has that mandate from The Father; see Jesus The Apostle and The Messiah's Mandate), but simply because Peter was more forward in personality. Peter often made statements or asked questions that Christ answered to all of them (e.g. see Bind and Loose).
The book of Acts is also known as "Acts of the apostles," but more specifically was the Acts of Peter and Paul. Acts focused on Peter until the calling of the Pharisee Saul, later known as Paul, to also be an apostle. From that point on, Acts, and most of the rest of the New Testament, records the ministry of Paul, with almost nothing recorded about Peter. Why? Did Paul replace Peter? No. Was Paul more important than Peter? No. The sole reason is because Paul was sent out to the "world," while Peter had the responsibility of serving the people of Judah, the Jews. Peter preached a national Gospel, while Paul preached "unto all the world." Paul's ministry was new ground (figuratively and literally - see Paul's First Missionary Journey, Paul's Second Missionary Journey and Paul's Third Missionary Journey) for the one true Gospel (see The Gospel of The Kingdom of God) that Peter also taught (e.g. see Peter's First Sermon; also Peter's Prophecy).
"They held their peace, and glorified God, saying, Then hath God also to the Gentiles granted repentance unto life"
Christianity began as a "Jewish" religion in that, from their view then (and still today), one must be a Jew in order to have the true religion - a view that is correct, if you happen to be a Jew, but not correct for the rest of humanity (keep in mind that the founding ancestors of the people of Israel and Judah were "gentiles" - see Abraham Wasn't A Jew; also Circumcision). Non-Jews don't have to become Jews to become the "chosen people" of the Messiah. Peter himself was given to realize it, in order that he recognize and accept what Paul was given to do. That turning point, the change of focus from Peter to Paul, occurred in Acts chapter 11 - with Peter's own words.
"11:1 And the apostles and brethren [see Prove To Be My Disciples] that were in Judaea heard that the Gentiles had also received the word of God. 11:2 And when Peter was come up to Jerusalem, they that were of the circumcision contended with him, 11:3 Saying, Thou wentest in to men uncircumcised, and didst eat with them.
Fact Finder: Will Israel exist after Christ's return?