Proposition:

Secondly, Godliness ought to be every man’s main business, because it is a work of the greatest concernment and weight. 

He here argues that the proposition is true. First, he restates it. This is “the tell them what you are going to tell them, tell them, tell them what you have told them.”

Things that are of most stress call for our greatest strength. Our utmost pains ought to be laid out upon that which is of highest price: man’s diligence about any work must be answerable to the consequence of the work. 

Varying the form of his argumentation, he here argues from the negative and does so in a mildly mocking manner. The first two examples are of people putting in tremendous effort to achieve a very small reward. The third example does not concern a wholly trivial event: at least you could eat the cooked egg. The example works by showing a complete mismatch between the effort expended and the result.

Also notice the structuring: he prefaces each example with a proverb or epigram: I have underscored the introductory proverb to make the structure clear: 

The folly of man seldom appears more than in being very busy about nothing, in making a great cry where there is little wool; like that empty fellow that shewed himself to Alexander—having spent much time, and taken much pains at it beforehand—and boasted that he could throw a pea through a little hole, expecting a great reward; but the king gave him only a bushel of peas for a recompense suitable to his diligent negligence or his busy idleness. 

Things that are vain and empty are unworthy of our care and industry. The man that by hard labour and hazard of his life did climb up to the top of the steeple to set an egg on end, was deservedly the object of pity and laughter. 

We shall think him little better than mad that should make as great a fire for the roasting of an egg as for the roasting of an ox.

He then pivots on the argument by stating it as a positive matter: we should give our best efforts to the most important ends. The illustration is curious, because rather than being an illustration which contains an argument in favor of our position, it is a picture of great burdens (and thus ends) requiring a great effort:

On the other side, the wisdom of men never presenteth itself to our view in livelier colours than in giving those affairs which are of greatest concernment precedency of time and strength. 

Of brutes man may learn this lesson: When the cart is empty, or hath but little lading, the team goeth easily along, they play upon the road; but when the burden is heavy, or the cart stuck, they pull, and draw, and put forth all their strength.

Notice how his many illustrations do not all function in same manner. This varying of the function of the illustrations helps by both avoiding tedium but also by addressing different readers. I find some illustrations more compelling or useful than others. But not all readers will have my personal response to the illustration.

He now applies the general proposition (our greatest effort should be directed to our greatest concern) to the question of godliness. He contends that godliness is our chief concern, because godliness effects not just our immediate existence, but rather eternal life. We 

Now godliness is, amongst all man’s works, of the greatest weight. The truth is, he hath no work of weight but this; this is the one thing necessary, and in this one thing are man’s all things. 

Our unchangeable weal or woe in the other world is wrapped up in our diligence or negligence about this; our earthly businesses, be they about food or raiment, about honours or pleasures, or whatsoever, are but toys and trifles, but baubles and butterflies, to this. As candles before the sun, they must all disappear and give place to this.

It is Your Life To prove the importance of godliness, Swinnock notes that this work of godliness is a matter of our life. To prove this he takes an argument taken from Moses’ Farewell Address. At the the end of Moses’ time with he ends with the note that the commandments set before them “is your life.”

Moses, a pious and tender father, when leaving them, in his swan-like song, gives savoury advice to his children. We need not doubt but his spiritual motions were quickest when his natural motions were slowest; that the stream of grace ran with full strength when it was to empty itself into the ocean of glory. Mark what special counsel he gives them who were committed to his special care: Deut. 32:46, ‘Set your hearts to all the words which I command you this day; for it is not a vain thing; because it is your life.’ 

In which words we have, 1. A commandment; and, 2. An argument. 

Here Swinnock draws Moses’ commandments to Swinnock’s thesis: the commandments are the instructions in godliness. Thus, to do the commandments is to exercise themselves to godliness:

The commandment is, ‘Set your hearts to all the words which I command you this day;’ that is, ‘Exercise yourselves to godliness.’ 

Here he presses on the point which marks many: I hear and understand but I do not do.

He doth not say, lend them your ears, to listen to them slightly; or let them have your tongues, to speak of them cursorily. No; it is not, set your heads, but set your hearts, to all the words, &c. He doth not say, Let your works be according to these words, or let your feet ever make them your walk; no, it is not set your hands, but set your hearts to the words that I speak unto you. Make it your business, and then your ears and tongues, your feet, your heads, your hands, and all will be employed about them to the purpose. 

The commandments are a matter of life and death:

But what special argument doth Moses urge for the enforcement of this great work? Surely that which I am speaking of, the weight of it: ‘Set your hearts to all the words which I command you this day; for it is not a vain thing; because it is your life,’ ver. 47.

Swinnock here uses an image to understand Moses’ work. If the heart of Israelites were wood, then it is very hard wood to split indeed.

Moses had experience that the hearts of the Israelites were exceeding knotty wood, and therefore he useth a heavy beetle to drive home the wedge: it is not a vain thing; it is life. As if he had said, Were it a matter of small moment, ye might laze and loiter about it; but it behoves you to bestir yourselves lustily to follow it, laboriously to set your hearts to it; for it is as much worth as your lives; that pearl of matchless price is engaged and at stake in your pursuit of godliness. 

At this point he gives a number of examples of how people will act to save their life. The implication is that if we would work so hard for our natural life, should we not work 

Life, though but natural, is of so much value that men will sacrifice their honours and pleasures, their wealth and liberty, and all to it.

The Egyptians parted with their costly jewels willingly to redeem their lives, as Calvin observeth. The widow in the Gospel spared none of her wealth to obtain health, which is much inferior to life: ‘Skin for skin, and all that a man hath, will he give for his life.’ 

Throw but a brute [an animal] into the water to drown it, how will it labour, and toil, and sweat, to preserve its life! View a man on his death-bed, when a distemper is, like a strong enemy, fighting to force life out of the field, how doth nature then, with all the might and strength it hath, strive and struggle to keep its ground! What panting and breathing, what sweating and working of all the parts do you behold! 

Here he applies the analogy: We work so hard to preserve our natural life which we must lose no matter the effort, then we should take greater care to preserve not the union of soul and body, but the union of our life and our Savior:

And no wonder—the man laboureth for life. If there be such labour for a natural life, that is but umbra vitæ, a shadow to this the substance, which is but the union of the body and soul, and lieth under a necessity of dissolution; what labour doth a spiritual life deserve, that consisteth in the soul’s union and communion with the blessed Saviour, and which neither men nor devils, neither death nor hell, shall ever deprive a believer of, but in spite of all it will grow and increase till it commence eternal life? 

Here he returns to his original proposition: It is your life:

Well might Moses expect that such a heavy weight as this should make great impression, and sink deep into their affections: ‘For it is not a vain thing; because it is your life.’