As the disciples of Christ spread and made new disciples different opinions made new groups with new leaders.
When talking about religions we particularly look at the independent and organised form of existence of a religion which one calls 'Church'.
Peter evidently did not view himself as the rock on which Jesus would build his congregation, since he wrote at 1Pe 2:4-8 that Jesus was the long-foretold “foundation cornerstone,” chosen by God himself. Similarly, the apostle Paul referred to Jesus as the “foundation” and “the spiritual rock.” (1Co 3:11; 10:4). For every Christian or follower of Christ their church or community should have Jesus as their cornerstone and not as such one or another hierarchical religious organisation.
For matters that happened in the first century of our common era historians of the first century like Tacitus, Josephus and later ancient writers like Africanus provided enough material to go and further Alexandrian manuscripts, findings from the Qumram caves and research from contemporary archaeologists and historians like Blomberg, Henry, Scott, Tabor, Droge, Ramsay, Samuelsson and many others.