The doctrine of the blessed Trinity may be considered two ways: First, In respect unto the revelation and proposal of it in the Scripture, to direct us unto the author, object, and end of our faith, in our worship and obedience. Secondly, As it is farther declared and explained, in terms, expressions, and propositions, reduced from the original revelation of it, suited whereunto, and meet to direct and keep the mind from undue apprehensions of the things it believes, and to declare them, unto farther edification.
In the first way, it consists merely in the propositions wherein the revelation of God is expressed in the Scripture; and in this regard two things are required of us. First, To understand the terms of the propositions, as they are enunciations of truth; and, Secondly, To believe the things taught, revealed, and declared in them.
In the first instance, no more, I say, is required of us, but that we assent unto the assertions and testimonies of God concerning himself, according to their natural and genuine sense, as he will be known, believed in, feared, and worshipped by us, as he is our Creator, Lord, and Rewarder; and that because he himself has, by his revelation, not only warranted us so to do, but also made it our duty, necessary and indispensable. Now, the sum of this revelation in this matter is, that God is one; — that this one God is Father, Son, and Holy Ghost; — that the Father is the Father of the Son; and the Son, the Son of the Father; and the Holy Ghost, the Spirit of the Father and the Son; and that, in respect of this their mutual relation, they are distinct from each other.
This is the substance of the doctrine of the Trinity, as to the first direct concernment of faith therein. The first intention of the Scripture, in the revelation of God towards us, is, as was said, that we might fear him, believe, worship, obey him, and live unto him, as God. That we may do this in a due manner, and worship the only true God, and not adore the false imaginations of our own minds it declares, as was said, that this God is one, the Father, Son, and Holy Ghost; — that the Father is this one God; and therefore is to be believed in, worshipped, obeyed, lived unto, and in all things considered by us as the first cause, sovereign Lord, and last end of all; — that the Son is the one true God; and therefore is to be believed in, worshipped, obeyed, lived unto, and in all things considered by us as the first cause, sovereign Lord, and last end of all; — and so, also, of the Holy Ghost. This is the whole of faith’s concernment in this matter, as it respects the direct revelation of God made by himself in the Scripture, and the first proper general end thereof. Let this be clearly confirmed by direct and positive divine testimonies, containing the declaration and revelation of God concerning himself, and faith is secured as to all it concerns; for it has both its proper formal object, and is sufficiently enabled to be directive of divine worship and obedience.
The explication of this doctrine unto edification, suitable unto the revelation mentioned, is of another consideration; and two things are incumbent on us to take care of therein:— First, That what is affirmed and taught do directly tend unto the ends of the revelation itself, by informing and enlightening of the mind in the knowledge of the mystery of it, so far as in this life we are, by divine assistance, capable to comprehend it; that is, that faith may be increased, strengthened, and confirmed against temptations and oppositions of Satan, and men of corrupt minds; and that we may be distinctly directed unto, and encouraged in, the obedience unto, and worship of God, that are required of us. Secondly, That nothing be affirmed or taught herein that may beget or occasion any undue apprehensions concerning God, or our obedience unto him, with respect unto the best, highest, securest revelations that we have of him and our duty. These things being done and secured, the end of the declaration of this doctrine concerning God is attained.
In the declaration, then, of this doctrine unto the edification of the church, there is contained a farther explanation of the things before asserted, as proposed directly and in themselves as the object of our faith, — namely, how God is one, in respect of his nature, substance, essence, Godhead, or divine being; how, being Father, Son, and Holy Ghost, he subsists in these three distinct persons or hypostases; and what are their mutual respects to each other, by which, as their peculiar properties, giving them the manner of their subsistence, they are distinguished one from another; with sundry other things of the like necessary consequence unto the revelation mentioned. And herein, as in the application of all other divine truths and mysteries whatever, yea, of all moral commanded duties, use is to be made of such words and expressions as, it may be, are not literally and formally contained in the Scripture; but only are, unto our conceptions and apprehensions, expository of what is so contained. And to deny the liberty, yea, the necessity hereof, is to deny all interpretation of the Scripture, — all endeavours to express the sense of the words of it unto the understandings of one another; which is, in a word, to render the Scripture itself altogether useless. For if it be unlawful for me to speak or write what I conceive to be the sense of the words of the Scripture, and the nature of the thing signified and expressed by them, it is unlawful for me, also, to think or conceive in my mind what is the sense of the words or nature of the things; which to say, is to make brutes of ourselves, and to frustrate the whole design of God in giving unto us the great privilege of his word.