It portrays Jesus as being very intolerant. He tells the Pharisees how they are doing everything wrong - worship, giving, praying, fasting, behaving, etc.
He upholds every letter and pen stroke of the Old Testament, something they typically abandon first.
He spoke of judgment. He emphatically shows that there are false religions - the very thing that the liberal theologians teach the opposite of. He warns strongly against false teachers - people like them!
It sets an impossibly high standard and demonstrates that we need a Savior to reach God. He raises the bar or shows the real intent behind prohibitions against adultery, murder, etc. and sums up that section by saying, Be perfect, therefore, as your heavenly Father is perfect (Matthew 5:48).
The problem is that the liberal theologians view it as a checklist, just as they do with Matthew 22:37-40 (“Love the Lord your God with all your heart and with all your soul and with all your mind . . . Love your neighbor as yourself.”). He didn’t mean for us to respond, “Thanks for the summary, I’ll get right on that!” The proper response is to be convicted that we can never be good enough on our own. You have to be pretty self-righteous not to realize what a joke it would be to claim you followed those passages well enough to merit God’s eternal favor.
In order to show that at least one liberal Christian has at least some inkling of how to read the Bible, let's stick with just the opening of Chapter 5, commonly known as the Beatitudes.
Before we even try to unpack all that, however, we need to take a step back and consider the Gospel of St. Matthew as a whole, and what purpose this passage serves in the author's overall narrative scheme. The writer of the Gospel sees the Christ-event as a recapitulation of the entire history of the people of Israel; every narrative moment, every event, each significant move is mirrored not only by analogy to events in the history of the people, but is accompanied by the writer's insistence that such-and-such an event is the fulfillment of this or that prophecy. On the one hand, this has led far too many people to think of "prophecy" as a kind of Divine divination, God predicting the future as it were. Another way of looking at this particular narrative device is to consider that it might just be a revolutionary rewriting of the entire Hebrew canon, centering it no longer on the people chosen by the LORD, called out of slavery; the center is now Jesus, the Son of Man (which embraces a later formulation, in the rebellious writings of Daniel, which were composed under the tyranny of Antiochus IV, about 150 years before Jesus was born), who embraces and transcends both the older history and tradition, as well as more recent yearning for freedom, independence, and the Kingdom of God.
This summary hardly does the subtlety of the Gospel justice, but we shall move now to the entire passage of Chapters 5-7. Simply put, this is, to use the terminology above, both an echo of and transcendence beyond the giving of the Law in Exodus. The Beatitudes echo the Ten Commandments to the extent that they offer a general view of the possibilities of a life lived in faith. They aren't rules. They aren't a new law. They aren't commandments. They are a description of God's gracious descent toward us, markers of the Kingdom of God, and the possibilities open to human beings who live in faith. We who mourn will be comforted. The meek shall inherit the earth. Those who hunger and thirst for righteousness will be filled. Those who work for peace will be called children of God. These are not demands, laws, decrees, or limits upon human action. They are a vision of life lived under the grace of God.
Speaking as one liberal United Methodist Christian, I just have to ask: What's not to like here?