Christian doctrine has been devalued for the last one hundred plus years. Liberal teachers continue to devalue it by inverting the relationship between Scripture and secular thought. They allow secular insights to interpret the Scripture. Evangelicals devalue doctrine by treating it as something that has little or nothing to do with living faithfully. ("It is not practical and only divides us anyway!") I have heard evangelicals say, most of my life, "Doctrine divides us but love unites us!"
A good example of this devaluing process, at least on the liberal side, is what we presently see happening regarding sexual ethics. The seventh commandment is quite clear. If you read what Christians teachers have said about this commandment since the first century the response would have been very, very consistent. But now, less than one decade into the twenty-first century, there is a huge debate about same-sex marriage. There really shouldn’t even be a debate. This debate can only thrive in a context where the role of Scripture has been inverted.
The real problem in this modern debate is that we have lost our way with regard to the clarity of Holy Scripture and the Christian tradition. The authentic Christian belief—still sustained by Roman Catholic, Orthodox and confessional Protestants—is that Holy Scripture is in essence God testifying to himself via human witnesses and God-breathed writers. (There is wide room here for differing views of how to define inspiration.) This belief that Scripture is God-breathed is basic, fundamental. Without it we can make no sense of Christianity. If the words of Scripture are not written revelation then we can know nothing of God’s truth revealed to us in Jesus Christ. We are cast adrift to interpret the Bible as we see fit in each age. (This is not to deny that we can rethink how we understand certain things in Scripture. It does mean that we cannot remake the commandments of God to fit into our modern ethical practice.)
The sum and substance of the church’s doctrine is found in the gospel itself. Our creator has become our redeemer through the incarnate Christ. But evangelicals have reduced this gospel to a few propositions; e.g., all have sinned, Jesus died and rose for sinners, believe on Jesus and you will be saved. This makes a valid point but the gospel includes much, much more. I would say, with many Christians down through the ages, that the Apostles’ Creed is a basic summary of the gospel. “The gospel,” says J. I. Packer, “is the full declaration of this gracious saving plan that God is fulfilling in and for his spoiled world, plus the full demonstration of the proper response—faith in Christ and repentance, good works, and love both Godward and manward, with gratitude and joyful hope.”
Intimately bound up with the gospel of Christ is the doctrine of the Trinity. The gospel saves us because, as J. I. Packer rightly notes: “the one tripersonal God, our God, operates as a team, all three persons within the divine unity working together in full conjunction with each other to carry through a single, huge, mind-blowing plan: namely, to establish a multi-billion strong community of redeemed human beings, each one an enormously complex entity in creational terms, within a fully reconstructed cosmos, with Jesus Christ the mediator at its center for all eternity.” I love those words: "a single, huge, mind-blowing plan."
The Anglican Prayer Book leads the worshiper to ask that God deliver us “from all false doctrine, heresy and schism.” Note all three: False doctrine, heresy and schism. They are uniquely related and we separate them to our own peril. Some Christians are concerned about false doctrine and heresy and care not at all about schism. The doctrine that establishes us in unity is the gospel and this gospel is intimately related to the Trinity. Without this framework Jesus is reduced to a cool plan of personal salvation. We cannot afford such reductionism since it will lead us further and further away from the doctrine of grace. Both liberals and evangelicals need this gospel and it will cost them something to make sure they regain it.