1. Because it is the foundation of all natural and revealed religion; and therefore it must not be received merely by tradition, as though there were no other reason why we believe it, but because others do so, or because we have been instructed herein from our childhood; for that is unbecoming the dignity and importance of the subject, and would be an instance of great stupidity, especially seeing we have so full and demonstrative an evidence thereof, taken from the whole frame of nature; in which there is nothing but what affords an argument to confirm our belief that there is a God.
2. There is a great deal of atheism in our hearts, by reason whereof we are prone sometimes to call in question the being, perfections, and providence of God. To which we may also add, that the Devil frequently injects atheistical thoughts into our minds; which is a great affliction to us, and renders it necessary that we should use all possible means for our establishment in this great truth.
3. The abounding of atheism in the world, and the boldness of many in arguing against this truth, renders it necessary that we should be able to defend it, that we may stop the mouths of blasphemers, and so plead the cause of God, and assert his being and perfections against those that deny them; as Psal. xiv. 1. The fool, who saith in his heart there is no God.
4. This will greatly tend to establish our faith in those comfortable truths that arise from our interest in him, and give us a more solid foundation for our hope, as excited by his promises, which receive all their force and virtue from those perfections which are implied in the idea of a God.
5. This will make us set a due value on his works, by which we are led to conclude his eternal power and Godhead, and so to admire him in them, Job xxxvi. 24. Remember that thou magnify his work, which men behold.
We shall now consider those arguments mentioned in this answer, by which the being of a God may be evinced; as,
I. From the light of nature in man, by which we understand that reason which he is endowed with, whereby he is distinguished from, and rendered superior to, all other creatures in this lower world, whereby he is able to observe the connexion of things, and their dependence on one another, and infer those consequences which may be deduced from thence. These reasoning powers, indeed, are very much sullied, depraved, and weakened, by our apostacy from God, but not wholly obliterated; so that there are some remains thereof, which are common to all nations, whereby, without the help of special revelation it may be known that there is a God.
But this either respects the principle of reasoning, which we were born with, upon the account whereof infants are called intelligent creatures; or the exercise thereof in a discursive way, in the adult, who only are capable to discern this truth, which they do more or less, in proportion to their natural capacity, as they make advances in the knowledge of other things. Now for the proof of the being of a God from the light of nature, let the following propositions be considered in their respective order.
1. There hath been, for many ages past, a succession of creatures in the world.[[9]]
2. These creatures could not make themselves, for that which is nothing cannot act; if it makes itself, it acts before it exists; it acts as a creator before it exists as a creature; and it must be, in the same respect, both a cause and an effect, or it must be, and not be, at the same time, than which nothing can be more absurd; therefore creatures were made by another, upon which account we call them creatures.