The text of (Acts 8.1) stresses a striking contrast:
“On that day a great persecution broke out against the church in Jerusalem; all, except the apostles, were scattered throughout the regions of Judea and Samaria.” (Acts 8.1)
Luke does not give the reason for this exception. Several explanations may nonetheless be put forward.
1- The apostles take up their responsibility as shepherds of the Church in Jerusalem
The most likely reason is pastoral. The Twelve received from Christ the responsibility of leading the young Church (John 21.15-17; Acts 2.42). Even though many believers flee to escape the persecution, a significant part of the community probably remains in Jerusalem. The apostles therefore choose to stay with the faithful in order to strengthen them and to preserve the unity of the Church.
This attitude recalls that of the good shepherd who does not abandon his flock in the moment of danger (John 10.11-13).
2- The authorities seek above all to dismantle the Church
The persecution seems to target first and foremost the whole Christian community. Saul “entered into every house, dragged off men and women, and committed them to prison” (Acts 8.3). The aim is to make the Christian movement disappear.
The apostles are certainly being sought, but their experience of earlier arrests has taught them that God could still protect them (Acts 5.17-20). They therefore do not flee immediately.
3- Their presence affirms that the Church is not abandoning Jerusalem
Jerusalem remains the starting point of the mission willed by Jesus (Acts 1.8). Had all the leaders left the city, this could have been interpreted as an abandonment of the Christian witness in the religious capital of Israel.
By remaining on the spot, the apostles show that the Gospel continues to be proclaimed in the very heart of the city where Jesus was crucified and raised.
4- They leave Jerusalem only once the mission is sufficiently established
The rest of the book of Acts shows that the apostles remain in Jerusalem for several more years. When Philip evangelizes Samaria, it is Peter and John who come to confirm this new work (Acts 8.14-17). Later, they are still the main leaders of the Church in Jerusalem at the time of Saul's conversion (Acts 9.26-28) and of the Council of Jerusalem (Acts 15.1-29).
Their presence thus ensures an apostolic continuity that was indispensable during the first years of the Church.
5- A dispersion that fulfills God's purpose
It is also possible that God led the apostles and the other disciples differently. The scattering of the believers makes possible the fulfillment of Jesus' promise:
“You will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the end of the earth.” (Acts 1.8)
The scattered disciples become the first missionaries in Judea and Samaria (Acts 8.4), while the apostles remain for the time being in Jerusalem to preserve the center of the Church. This division of roles contributes to the harmonious expansion of Christianity.
A complementary historical hypothesis
Some exegetes put forward an additional explanation. The may have concentrated their efforts on Greek-speaking believers (the Hellenists), of whom Stephen was one of the most prominent figures (Acts 6.1; Acts 6.8-15). This hypothesis would explain why the dispersion first affects a large part of the Church, while the apostles, all of Hebrew origin and already well known to the authorities, remain in Jerusalem for the time being.
However, this interpretation remains hypothetical. Luke's text does not specify that the persecution targeted the Hellenists exclusively. It simply states that the apostles were not scattered with the other believers.
Conclusion
Luke never explicitly gives the exact reason. Nevertheless, the whole account leads us to think that the apostles remain in Jerusalem chiefly to provide spiritual leadership for the mother Church, to maintain the witness at the heart of Judaism, and to guarantee the doctrinal unity of the Christian community, while the scattering of the other disciples becomes the providential instrument for spreading the Gospel in Judea and Samaria. This complementarity illustrates the sovereignty of God, who turns a violent persecution into a powerful means of accomplishing his missionary plan.