20. If you rightly apprehend this short account of the union of the soul and body, you will see a great deal into the reason of all the outward parts of religion.
This union of our souls and bodies, is the reason both why we have so little and so much power over ourselves. It is owing to this, that we have so little power over our souls: for as we cannot prevent the effects of external objects upon our bodies; as we cannot command outward causes; so we cannot always command the inward state of our minds; because, as outward objects act upon our bodies without our leave, so our bodies act upon our minds by the laws of the union vital. And thus you see it is owing to this union, that we have so little power over ourselves.
On the other hand, it is owing to this union, that we have so much power over ourselves. For as our souls in a great measure depend upon our bodies; and as we have great power over these; as we can mortify our bodies, and remove ourselves from objects that inflame our passions; so we have a great power over the inward state of our souls. Again, as the outward acts of reading, praying, singing, and the like, have an effect upon the soul; so by being masters of these outward, bodily actions, we have great power over the inward state of the heart.
And thus it is owing to this union, that we have so much power over ourselves.
Now from this you may see the benefit of singing psalms, and of all the outward acts of religion; for if the body has so much power over the soul, all such bodily actions as affect the soul, are of great weight in religion, because they are proper to support that spirit, which is the true worship of God.
21. This doctrine may be easily carried too far; for by calling in too many outward means of worship, it may degenerate into superstition. But some have fallen into the contrary extreme. Because religion is justly placed in the heart, they renounce vocal prayer, and other outward acts of worship, and resolve all religion into a quietism, or mystic intercourse with God in silence.
But since we are neither all soul, nor all body; seeing none of our actions are either separately of the soul, or separately of the body; if we would truly prostrate ourselves before God, we must use our bodies to postures of lowliness. If we desire true fervours of devotion, we must make prayer the frequent labour of our lips. If we would feel inward joy and delight in God, we must practise all the outward acts of it, and make our voices call upon our hearts.
Now therefore, you may plainly see the reason of singing of psalms; it is because outward actions are necessary to support inward tempers.
22. I have been the longer upon this head, because of its importance to true religion. For there is no state of mind so excellent, as that of thankfulness to God; and consequently, nothing is of more importance than that which exercises and improves this habit of mind.
*An uneasy, complaining spirit, which is sometimes the spirit of those that seem careful of religion, is yet of all tempers the most contrary to religion; for it disowns that God which it pretends to adore. For he sufficiently disowns God, who does not adore him as a being of infinite goodness.