The following extract is from John Owen's book "The Grace and Duty of being Spiritually Minded". It is a very striking piece and deals with objections to fixing the thoughts consistently upon spiritual things, particularly the objection that we do not have time to devote to this duty. (See also the last post from John Owen in relation to this objection.) Owen contends that we owe to God the best and most of our time. He shows how we can be spiritually-minded and diligent in our work.
Some, it may be, will say, that if all these things are required thereunto, it will take up a man’s whole life and time to be spiritually minded. They hope they may attain it at an easier rate, and not forego all other advantages and sweetnesses of life, which a strict observation of these things would cast them upon.
I answer, that however it may prove a hard saying unto some, yet I must say it, and my heart would reproach me if I should not say, that if the principal part of our time be not spent about these things, whatever we suppose, we have indeed neither life nor peace. The first-fruits of all were to be offered unto God; and in sacrifices he required the blood and the fat of the inwards. If the best be not his, he will have nothing. It is so as to our time. Tell me, I pray you, how you can spend your time and your lives better, or to better purpose, and I shall say, Go on and prosper. I am sure some spend so much of their time so much worse as it is a shame to see it. Do you think you came into this world to spend your whole time and strength in your employments, your trades, your pleasures, unto the satisfaction of the "wills of the flesh and of the mind?" Have you time enough to eat, to drink, to sleep, to talk unprofitably, it may be corruptly, in all sorts of unnecessary societies, but have not enough to live unto God in the very essentials of that life which consists in these things? Alas! you came into the world under this law, "It is appointed to men once to die, and after this the judgment," Hebrews 9:27; and the end why your life is here granted unto you is that you may be prepared for that judgment. If this be neglected, if the principal part of your time be not improved with respect unto this end, you will fall under the sentence of it unto eternity.
But men are apt to mistake in this matter. They may think that these things tend to take them off from their lawful employments and recreations, which they are generally afraid of, and unwilling to purchase any frame of mind at so dear a rate. They may suppose that to have men spiritually minded, we would make them mopes, and to disregard all the lawful occasions of life...The generality of Christians have lawful callings, employments, and businesses, which ordinarily they ought to abide in. That they also may live unto God in their occasions, they may do well to consider two things: —
(1.) Industry in men’s callings is a thing in itself very commendable. If in nothing else, it hath an advantage herein, that it is a means to preserve men from those excesses in lust and riot which otherwise they are apt to run into. And if you consider the two sorts of men whereinto the generality of mankind are distributed, — namely, of them who are industrious in their affairs, and those who spend their time, so far as they are able, in idleness and pleasure, — the former sort are far more amiable and desirable. Howbeit it is capable of being greatly abused. Earthly mindedness, covetousness, devouring things holy as to times and seasons of duty, uselessness, and the like pernicious vices, do invade and possess the minds of men. There is no lawful calling that doth absolutely exclude this grace of being spiritually minded in them that are engaged in it, nor any that doth include it. Men may be in the meanest of lawful callings and be so, and men may be in the best and highest and not be so. Consider the calling of the ministry: The work and duty of it calls on those that are employed in it to have their minds and thoughts conversant about spiritual and heavenly things. They are to study about them, to meditate on them, to commit them to memory, to speak them out unto others. It will be said, "Surely such men must needs be spiritually minded." If they go no farther than what is mentioned, I say they must needs be so as printers must needs be learned, who are continually conversant about letters. A man may with great industry engage himself in these things, and yet his mind be most remote from being spiritual. The event doth declare that it may be so. And the reasons of it are manifest. It requires as much if not more watchfulness, more care, more humility, for a minister to be spiritually minded in the discharge of his calling, than for any other sort of men in theirs; and that, as for other reasons, so because the commonness of the exercise of such thoughts, with their design upon others in their expression, will take off their power and efficacy. And he will have little benefit by his own ministry who endeavors not in the first place an experience in his own heart of the power of the truths which he doth teach unto others. And there is evidently as great a failing herein among us as among any other sort of Christians, as every occasion of trial doth demonstrate.
(2.) Although industry in any honest calling be allowable, yet unless men labour to be spiritually minded in the exercise of that industry, they have neither life nor peace. Hereunto all the things before mentioned are necessary; I know not how any of them can be abated; yea, more is required than is expressed in them. If you burn this roll, another must be written, and many like things must be added unto it. And the objection from the expense of time in the observance of them is of no force; for a man may do as much work whilst he is spiritually minded as whilst he is carnal. Spiritual thoughts will no more hinder you in your callings than those that are vain and earthly, which all sorts of men can find leisure for in the midst of their employments. If you have filled a vessel with chaff, yet you may pour into it a great deal of water, which will be contained in the same space and vessel; and if it be necessary that you should take in much of the chaff of the world into your minds, yet are they capable of such measures of grace as shall preserve them sincere unto God.