Matthew has opened the New Testament in Greek manuscript order since at least the 2nd century, even though most scholars now regard Mark as the earlier composition. Its early prominence owes to its usefulness: heavily structured, quotation dense, and pitched toward a community negotiating its Jewish inheritance, it became the church's primary teaching text long before questions of composition order were asked. Its language echoes through the earliest post-New Testament writings, including the Didache, and the Sermon on the Mount has supplied the core of Christian ethical instruction across every later tradition, Catholic, Orthodox, and Protestant alike. In the Catholic and many Protestant lectionaries, Matthew supplies most of the Sunday readings for Year A of the three year cycle.
The Gospel also carries the New Testament's clearest statement of ecclesial authority: "where two or three are gathered in my name, there am I among them" and the disciplinary procedure that surrounds it, in chapter 18, shaped how early congregations understood their own power to resolve disputes. Its most consequential single verse may be 16:18, "on this rock I will build my church," unique to Matthew and read very differently across the traditions that inherit it: Catholic teaching finds in it the foundation of the papacy through Peter's office, while Orthodox and Protestant readings locate the "rock" in Peter's confession of faith rather than in Peter's person, a live doctrinal divide the text itself does not resolve.