There are some differences between the Gospel accounts that critics of Christianity say are contradictions and mean that while we might be able to know Jesus existed, we can’t accept the claim that Jesus is the son of God, or he really did miracles, and its not generally reliable.
But while we already know that if two stories are identical, we might suspect collusion, another important thing to note was that while there might be perceived differences in the gospel accounts, these differences are well within the expected writing style of the time and actually add to their first century legitimacy. Of course, paper was not a limitless resource 2000 years ago and most biographies of people were written with the intention that it could be read to an audience in 2-3 hours, so paraphrasing events, summarising, spotlighting were all techniques expected of writers of antiquities.
For instance, after the resurrection of Jesus in the Gospel of Luke, it states Peter ran to the tomb, whereas in the Gospel of John, it states Peter AND John ran to the tomb. So was it just Peter, or was it Peter and John? Just because John is omitted in Luke’s account, doesn’t mean he wasn’t there. In fact, slightly later in Luke 24:24 Luke writes: “Some of those who were with us went to the tomb and found it just as the women had said, but him they did not see.””
So while Luke specially mentions just Peter in earlier verses, now he is mentioning a plurality of people visiting the tomb after the women reported the empty tomb. Just because Luke spotlighted Peter, doesn’t mean John was not also there. It was expected of writers of ancient times, specifically in Greek antiquities, to shorten, paraphrase, highlight and spotlight key events, and the style of writing places these written accounts right in the time and location we would expect.