There are many who would proclaim that doctrine doesn't matter or isn't as important as being loving or living rightly. However, the very problem with that thought is that you cannot live rightly and love others unless your mind has been transformed to the things of Christ. For instance, if the apostle Paul had cared more about living rightly and loving others, do you think that he would have written all of the letters that he did to all of the churches that he did exhorting them to hold fast to the truth and to remember what he had taught them? If they needed to only live right, then they wouldn't need to remember what he had taught them, but rather they would have merely attempted to live by their own merit.
I think that A.W. Tozer lays out an amazing argument as to why doctrine matters. He says:
"It would be impossible to overemphasize the importance of sound doctrine in the life of a Christian. Right thinking about all spiritual matters is imperative if we would have right living. As men do not gather grapes of thorns nor figs of thistles, sound character does not grow out of unsound teaching.
The word doctrine means simply religious beliefs held and taught. It is the sacred task of all Christians, first as believers and then as teachers of religious beliefs, to be certain that these beliefs correspond exactly to truth. A precise agreement between belief and fact constitutes soundness in doctrine. We cannot afford to have less.
The apostles not only taught truth but contended for its purity against any who would corrupt it. The Pauline epistles resist every effort of false teachers to introduce doctrinal vagaries. John’s epistles are sharp with condemnation of those teachers who harassed the young church by denying the incarnation and throwing doubts upon the doctrine of the Trinity; and Jude in his brief but powerful epistle rises to heights of burning eloquence as he pours scorn upon evil teachers who would mislead the saints.
Each generation of Christians must look to its beliefs. While truth itself is unchanging, the minds of men are porous vessels out of which truth can leak and into which error may seep to dilute the truth they contain. The human heart is heretical by nature and runs to error as naturally as a garden to weeds. All a man, a church or a denomination needs to guarantee deterioration of doctrine is to take everything for granted and do nothing. The unattended garden will soon be overrun with weeds; the heart that fails to cultivate truth and root out error will shortly be a theological wilderness; the church or denomination that grows careless on the highway of truth will before long find itself astray, bogged down in some mud flat from which there is no escape.
In every field of human thought and activity accuracy is considered a virtue. To err ever so slightly is to invite serious loss, if not death itself. Only in religious thought is faithfulness to truth looked upon as a fault. When men deal with things earthly and temporal they demand truth; when they come to the consideration of things heavenly and eternal they hedge and hesitate as if truth either could not be discovered or didn’t matter anyway.
Montaigne said that a liar is one who is brave toward God and a coward toward men; for a liar faces God and shrinks from men. Is this not simply a proof of unbelief? Is it not to say that the liar believes in men but is not convinced of the existence of God, and is willing to risk the displeasure of a God who may not exist rather than that of man who obviously does?
I think also that deep, basic unbelief is back of human carelessness in religion. The scientist, the physician, the navigator deals with matters he knows are real; and because these things are real the world demands that both teacher and practitioner be skilled in the knowledge of them. The teacher of spiritual things only is required to be unsure in his beliefs, ambiguous in his remarks and tolerant of every religious opinion expressed by anyone, even by the man least qualified to hold an opinion.
Haziness of doctrine has always been the mark of the liberal. When the Holy Scriptures are rejected as the final authority on religious belief something must be found to take their place. Historically that something has been either reason or sentiment: if sentiment, it has been humanism. Sometimes there has been an admixture of the two, as may be seen in liberal churches today. These will not quite give up the Bible, neither will they quite believe it; the result is an unclear body of beliefs more like a fog than a mountain, where anything may be true but nothing may be trusted as being certainly true.
We have gotten accustomed to the blurred puffs of gray fog that pass for doctrine in modernistic churches and expect nothing better, but it is a cause for real alarm that the fog has begun of late to creep into many evangelical churches. From some previously unimpeachable sources are now coming vague statements consisting of a milky admixture of Scripture, science and human sentiment that is true to none of its ingredients because each one works to cancel the others out.
Certain of our evangelical brethren appear to be laboring under the impression that they are advanced thinkers because they are rethinking evolution and reevaluating various Bible doctrines or even divine inspiration itself; but so far are they from being advanced thinkers that they are merely timid followers of modernism-fifty years behind the parade.
Little by little evangelical Christians these days are being brainwashed. One evidence is that increasing numbers of them are becoming ashamed to be found unequivocally on the side of truth. They say they believe but their beliefs have been so diluted as to be impossible of clear definition.
Moral power has always accompanied definitive beliefs. Great saints have always been dogmatic. We need right now a return to a gentle dogmatism that smiles while it stands stubborn and firm on the Word of God that liveth and abideth forever."
from: Man: The Dwelling Place of God, A.W. Tozer.
Oh how true these words are today. It would seem as if he had written them about today's Christian church, and these words were written over fifty years ago. May our hearts ache for those who disregard the very foundation that they claim to stand on and forsake the sacrifices that those saints who have gone before us paid with their blood to preserve many works that contain deep and beautiful doctrines that cause the Christian to taste sweet honey from our Father's hand.