The following excerpt is from John Owen’s discourse on the Grace and Duty of Being Spiritually Minded:
“Thoughts and meditations as proceeding from spiritual affections are the first things wherein this spiritual mindedness doth consist, and whereby it doth evidence itself. Our thoughts are like the blossoms on a tree in the spring. You may see a tree in the spring all covered with blossoms, so that nothing else of it appears. Multitudes of them fall off and come to nothing. Oft times where there are most blossoms there is least fruit. But yet there is no fruit, be it of what sort it will, good or bad, but it comes in and from some of those blossoms. The mind of man is covered with thoughts, as a tree with blossoms. Most of them fall off, vanish, and come to nothing, end in vanity; and sometimes where the mind doth most abound with them there is the least fruit; the sap of the mind is wasted and consumed in them. Howbeit there is no fruit which actually we bring forth, be it good or bad, but it proceeds from some of these thoughts. Wherefore, ordinarily, these give the best and surest measure of the frame of men’s minds. “As a man thinketh in his heart, so is he,” Prov. xxiii. 7.
In case of strong and violent temptations, the real frame of a man’s heart is not to be judged by the multiplicity of thoughts about any object, for whether they are from Satan’s suggestions, or from inward darkness, trouble, and horror, they will impose such a continual sense of themselves on the mind as shall engage all its thoughts about them; as when a man is in a storm at sea, the current of his thoughts run quite another way than when he is in safety about his occasions. But ordinarily, voluntary thoughts are the best measure and indication of the frame of our minds. As the nature of the soil is judged by the grass which it brings forth, so may the disposition of the heart by the predominancy of voluntary thoughts; they are the original actings of the soul, the way whereby the heart puts forth and empties the treasure that is in it, the waters that first rise and flow from that fountain.
Every man’s heart is his treasury, and the treasure that is in it is either good or evil, as our Saviour tells us. There is a good and bad treasure of the heart; but whatever a man hath, be it good or evil, there it is. This treasure is opening, emptying, and spending itself continually, though it can never be exhausted; for it hath a fountain, in nature or grace, which no expense can diminish, yea, it increaseth and getteth strength by it. The more you spend of the treasure of your heart in any kind, the more will you abound in treasure of the same kind. Whether it be good or evil, it grows by expense and exercise; and the principal way whereby it puts forth itself is by the thoughts of the mind. If the heart be evil, they are for the most part vain, filthy, corrupt, wicked, foolish; if it be under the power of a principle of grace, and so have a good treasure in it, it puts forth itself by thoughts suitable unto its nature and compliant with its inclinations.”