That there are four gospels rather than one is a decision, and it was contested. Marcion around 144 wanted one, an edited Luke, and was expelled. Tatian around 170 wove all four into a single continuous narrative, the Diatessaron, which became the standard gospel text of the Syriac church for two centuries until bishops replaced it and destroyed the copies. Irenaeus, writing about 180, argued that four is the necessary number because there are four zones of the world and four winds, an argument nobody now finds persuasive and which nonetheless describes what the church did. The result is that Christianity's foundational documents openly disagree — on the day of the crucifixion, on the genealogies, on who arrived at the tomb — and the church chose to live with that rather than tidy it. Mark is now generally reckoned the earliest and shortest; Matthew and Luke used Mark and a shared body of sayings; John comes from a different stream entirely and is where most of the high Christology lives.