We read last week that God does indeed have a plan, and that he is able to communicate it to us. But there is much confusion about how he accomplishes that. Packer writes on How We Receive Guidance:

Earnest Christians seeking guidance often go wrong. Why is this? Often the reason is that their notion of the nature and method of divine guidance is distorted. They look for a will-o’-the-wisp; they overlook the guidance that is ready at hand and lay themselves open to all sorts of delusions. Their basic mistake is to think of guidance as essentially inward prompting by the Holy Spirit, apart from the written Word. This idea . . . is a seed-bed in which all forms of fanatacism and folly can grow.
   How do thoughtful Christians come to make this mistake? What seems to happen is this. They hear the word guidance and think at once of a particular class of “guidance problems”—on which, perhaps, the books they have read and the testimonies they have heard tended to harp exclusively. This is the class of problems concerned with what we may call “vocational choices”—choices, that is, between competing options, all of which in themselves appear lawful and good. Should I contemplate marriage, or not? Should I marry this person, or not? . . . Should I serve God in the land of my upbringing, or abroad? Which of the professions open to me should I follow? . . . Is my present sphere of work the right one to stay in? . . . Which claims on my voluntary service time should have priority?
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   Two features about divine guidance in the case of “vocational choices” are distinctive. Both follow from the nature of the situation itself. First, these problems cannot be resolved by a direct application of biblical teaching. All one can do from Scripture is circumscribe the lawful possibilities between which the choice has to be made. (No biblical text, for instance, told the present writer to propose to the lady who is now his wife, or to seek ordination, or to start his ministry in England, or to buy his large old car.)
   Second, just because Scripture cannot decide one’s choice directly, the factor of God-given prompting and inclination, whereby one is drawn to commit oneself to one set of responsibilities rather than another and finds one’s mind settled in peace as one contemplates them, becomes decisive. The basis of the mistake which we are trying to detect is to assume, first, that all guidance problems have these same two characteristics, and, second, that all life should be treated as a field in which this kind of guidance should be sought.
   The consequences of this mistake among earnest Christians have been both comic and tragic. The idea of a life in which the inward voice of the Spirit decides and directs everything sounds most attractive, for it seems to exalt the Spirit’s ministry and to promise the closest intimacy with God; but in practice this quest for superspirituality leads only to frantic bewilderment or lunacy.
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   But the true way to honor the Holy Spirit as our guide is to honor the holy Scriptures through which he guides us. The fundamental guidance which God gives to shape our lives—the instilling, that is, of the basic convictions, attitudes, ideals and value judgments, in terms of which we are to live—is not a matter of inward promptings apart from the Word but of the pressure on our consciences of the portrayal of God’s character and will in the Word, which the Spirit enlightens us to understand and apply to ourselves.
   The basic form of divine guidance, therefore, is the presentation to us of positive ideals as guidelines for all our living. “Be the kind of person that Jesus was”; “seek this virtue, and this one, and this, and practice them up to the limit”; “know your responsibilities—husbands, to your wives; wives, to your husbands; parents, to your children; all of you, to all your fellow Christians and all your fellow human beings; know them, and seek strength constantly to discharge them”—this is how God guides us through the Bible, as any student of the Psalms, the Proverbs, the Prophets, the Sermon on the Mount, and the ethical parts of the Epistles will soon discover. “Turn from evil and do good” (Psalm 34:14; 37:27)—this is the highway along which the Bible is concerned to lead us, and all its admonitions are concerned to keep us on it. Be it noted that the reference to being “led by the Spirit” in Romans 8:14 relates not to inward “voices” or any such experience, but to mortifying known sin and not living after the flesh!
   Only within the limits of this guidance does God prompt us inwardly in matters of “vocational” decision. So never expect to be aided to marry an unbeliever, or elope with a married person, as long as 1 Corinthians 7:39 and the seventh commandment stand! The present writer has known divine guidance to be claimed for both courses of action. Inward inclinations were undoubtedly present, but they were quite certainly not from the Spirit of God, for they went against the Word. The Spirit leads within the limits which the Word sets, not beyond them. “He guides me in paths of righteousness” (Ps 23:3)—but not anywhere else.

—J. I. Packer, Knowing God (InterVarsity Press, 1993), 233–237.