The Sermon on the Mount ends by pushing very hard the idea that there are two ways of life. There are two gates, one wide and one narrow, leading to either death or life (Matthew 7:13-14). There are the two kinds of trees, one producing good fruit and one producing bad fruit (7:15-20). There is the fate of those who falsely claim Jesus as Lord at the judgment. We only hear about the negative fate in 21-23, but there clearly are those who get welcomed into the kingdom. Finally, there is the parable of the builders who built on sand or rock (7:24-27).
You see the two ways not only in the Sermon on the Mount but throughout Matthew’s gospel. Think of the parables of the ten bridesmaids and the sheep and the goats in chapter 25.
I studied under the late professor, M. Jack Suggs. He saw the roots of the two ways tradition in Zoroastrian dualism. It came over into Judaism and functioned to maintain group identity by distinguishing the behavior of insiders from outsiders. (The Christian Two Ways Tradition: Its Antiquity, Form, and Function. In Studies in New Testament and Early Christian Literature: Essays in Honor of Allen P. Wikgren. 1972).
Dale Allison sees the emphasis on the two ways here at the end of the Sermon on the Mount as a way of summing up:
“There are those who give and pray and fast rightly and those who do not. (6:1-8). There are those with light within and darkness within (6:22-23). There are those who serve God and those who serve mammon (6:19-34). All these antitheses do not mean that everything is black or white. Rather, the severe alternatives awake us to the urgent lesson that one must choose clearly and unambiguously–and if necessary at great personal cost–when the issue is the kingdom” (p. 165).
The two ways have to do with actions and behavior. This is a problem for Protestant theology that wants to make everything depend upon faith. But Allison (he is Protestant) thinks the Roman Catholic tradition of interpretation here is more faithful. Deeds matter. Ethics matter. It is pretty hard to read Matthew’s gospel and think otherwise.
In an epilogue, Allison talks about H. Richard Niebuhr’s three ways to do social ethics. The church could champion “Christ against culture”. Or it could take the position of “Christ of culture”. There is also a mediating approach which Niebuhr called “the church of the center”. This typology can help us understand how the church has historically interpreted the Sermon on the Mount.
Allison has opted for a mediating approach. This puts him in the tradition of Augustine, Aquinas, Luther, and Calvin. The basis for this is giving much force to Matthew 5:17-20. Thus the Sermon on the Mount comes to us not to uproot all that went before. It comes to us in our present situation where Christ and culture lay sometimes incompatible claims upon us. This leaves us all with the serious task of hearing the Sermon on the Mount, praying, and choosing with fear and trembling to act faithfully.
I appreciate Allison’s approach. I especially have appreciated his bringing out that we have hyperbole, humor, and parables that appeal to the imagination. Thus we can’t treat the Sermon as a legal code or an instruction book for personal or political life. The Sermon is part of Matthew’s gospel, which is primarily narrative leading up to the crucifixion and resurrection. The Sermon causes us to wrestle with what it means to follow the one of whose story it is a part.