What is the Trinity and why is it important?

Here in this very majestic declaration of the Oneness of the Godhead, care is taken to state it consistently with the truth afterwards revealed concerning the Three Persons of the Godhead—Father, Son and Spirit. These Three Persons, of one Substance, completely united in thought, will, purpose, counsel, are not three Gods, but One God, not a tritheism, but a Holy Trinity. We cannot understand the mystery of all this, but this truth lies at the very foundation of the Christian faith.

This, then, leads us to the great and vital truth of the Trinity; though in so brief a work as this, I cannot possibly linger over the doctrine as I would desire. Now, even though it be allowed there were intimations in the Old Testament of the doctrine, yet God was not revealed in Trinity until the Son had come. Only by the presence of the Son of God on earth could the knowledge of the Father be revealed. We know the Father in and by the Son. The Father bears witness to His beloved Son, and the Son makes known the Father. What God is, He ever has been and ever will be. The Divine Trinity of the revelation of Christianity, Father, Son, and Holy Spirit, is that doctrine which, whilst it safeguards the Unity of God, yet makes known to us Three Persons in that eternal Unity. Further, this word "Person" must only be used by us with great spiritual caution. We must on no account use it in regard of God as we use it in regard to ourselves; that is, in a limited sense, and with a strong individualistic meaning. To do so will result in a complete loss of the truth of the Divine Unity. Now this doctrine must be maintained at all costs. "God is one." "There is one God." Scripture is unanimous in its witness to this solemn fundamental doctrine regarding God. And the eternal relations of the Trinity, the Son — begotten, and the Holy Spirit — proceeding, preserve this truth of the Divine Unity. And if we deny these eternal relations we have cast away our anchors, and there is nothing to prevent us going to pieces on the rocks of heresy and gross error. Because, if the revealed relations of the Godhead be denied, we have not a vestige of right to suppose or to imagine that any others existed. To reject what God reveals of Himself because of some difficulty in our minds founded on human relations, and then to suppose something else, no man knows what, to be true of God, is in fact to make Him a liar. The entire testimony of the written Word is to the effect that our Lord Jesus Christ is the true Son of God, that the relation of the Father and the Son is a real relation, essentially Divine and Personal, and hence necessarily Eternal. To doubt this is to doubt about everything. For if God by His Spirit has not rendered a certain testimony to His own Son, but one of such terrible uncertainty that the whole Church has been deceived and in error for some 1900 years, then, I say, we have no moral foundation for our faith in any other Divine testimony.

The Holy Ghost is a separate Personality in God. His Name is seen in conjunction with the names of the Father, and the Son, in Matthew 28 Christian baptism commits one to the confession of God as revealed by Christ, the full revelation of the one true living God being Father, Son, and Holy Ghost. There are not two Gods, or three Gods, as ignorant objectors allege; but three Personalities in one God. These three ever subsisted in the Godhead; and with regard to the Holy Spirit, He is expressly called the Eternal Spirit (Heb. 9:14). Before the worlds were made, God is (Heb. 11:3, 6); but even when heaven and earth were created these material things were not capable of bringing to light all that God is. Moreover, though Enoch and Noah walked with God, and Abraham was called God's friend, and the lord spake face to face unto Moses as a man speaks to his friend, their great intimacies did not bring to light the full truth. He was known to the patriarchs under His name of Almighty God, for the attribute of All-might pertains to the whole Godhead. Later, an advance was made when God especially linked His name of Jehovah with the nation of Israel (Exodus 6:2-3), for eternal existence and unchangeable glory (which are implied in that name) belong equally to the whole Godhead. Yet amid all the glories unfolded by the prophets, the Godhead secret w as never fully disclosed until in the fulness of time Christ came When it was no longer a question of the creation of worlds, or of the power that could sustain faith and reward it, as in Old Testament times, but rather of making purgation of sin and of revealing all that God is, the appearance of the Son of God in a concrete human form, apart from sin, necessarily brought to light His relations with the other Persons in the Trinity. Christianity therefore is based upon the knowledge of God as Father, Son, and Holy Ghost.

Thus we see that there could be no full revelation of God, but through the Son by the Spirit, and thereby of the Father. The full revelation of the one God is only thus - Father, Son, and Holy Ghost. This, this only, is what the one God is, one identity of will and being, so that they are essentially one and one only, yet distinct in willing and acting (and we can distinguish them in willing and acting: hence we commonly speak of persons), yet never willing or acting but in the common will and unity of nature.

I fear much human language on this. But I affirm that the only full revelation of the one true God is the revelation of Him in the Trinity. Our prayers rise up the same. Through Him (Christ the Son) we have access by one Spirit unto the Father.

So we must be careful in using the terms, first, second and third Persons in the Trinity, not to think there is any difference in importance. The Father is God; the Son is God; the Spirit is God—the Spirit equal in nature and substance to the Father and the Son. If the three Persons of the Godhead are each of them God, it does not follow that there are three Gods. That were impossible. There can be only one God, supreme and unique. Orthodox Christendom believes in three Persons in the Godhead, yet one God, indivisible and unique—the three Persons in the Godhead with one will, one purpose, each sharing to the full every thought and desire and purpose in the minds of the others. We may not, nay cannot, comprehend this. It is a mystery hidden in the Godhead, yet the Godhead is pleased to reveal Itself as Father, Son, and Holy Spirit.

Scripture is most plain, whatever unbelief may say, that there are three distinct persons in the Godhead, equal in power, majesty, and glory, each taking His own part in all that is done, whether in creation or redemption, yet ever acting in perfect unity and communion.

We are speaking of our Lord Jesus Christ as “the Son,” and not of His distinctive glories as “the Son of David,” “the Son of Man” and “the Son of God,” nor even of Him as “the Son of the Father,” but rather of His deity as God the Son. The Father is God, the Son is God, and the Holy Spirit is God; yet there are not three Gods, but one God, “God is one” (Gal. 3:20; 1 Tim. 2:5, N.Tr.). Baptism is to the name of the Father and of the Son and of the Holy Spirit,” we are told in Matthew 28:19. This indicates for us the trinity of Persons in the Godhead, all of whom share in that supreme glory.

Whilst it is true that nowhere in Scripture is it asserted in so many words that the Holy Spirit is God, yet the way in which the names of the Father, Son and Spirit are linked together, shows plainly the truth of the Deity of the Spirit with that of the Father and the Son. Believers are baptized “in the name of the Father, and of the Son and of the Holy Ghost” (Matt. 28:19). Could that formula be employed if it were not that the Spirit is God, as the Father is God and the Son is God? Then there is the charming benediction, “The grace of our Lord Jesus Christ, and the love of God, and the communion of the Holy Ghost, be with you all. Amen” (2 Cor. 13:14). One well-known passage we refer to, 1 Corinthians 12:11, where absolute sovereignty, an attribute only proper to Deity, is predicated of the Holy Spirit, “But all these works that one and the selfsame Spirit, dividing to every man severally AS HE WILL.” This is language only proper to God Himself. There is also one very striking passage where the fullest intimation of the Holy Trinity to be found in the Old Testament is given: “Come ye near unto Me, hear ye this; I have not spoken in secret from the beginning; from the time that it was there am I [a Divine Person] and now the Lord God and His Spirit has sent Me” (Isa. 48:16). (1) The Lord God, (2) His Spirit, (3) Me, three Persons in the Holy Trinity. How often the Lord when on earth spoke of Himself as the SENT One.

There are three Persons in the Godhead—Father, Son and Holy Spirit. Till the Lord Jesus revealed the Father by His coming into this world as the Son sent of the Father, God was not known in His fulness. Moreover, it waited the advent of the Spirit of God on the day of Pentecost to complete the fulness of the revelation in the apprehension of the believer, for the Holy Spirit is the power by which these things are known and enjoyed.

The very notion of Christianity is above human thought till God revealed it. Others have concerned God's appearing in human form to steal, to kill, to indulge lust or other evil. Such were the ideas of Greeks and Romans. Scripture alone reveals God assuming human nature without sin to be a sacrifice for sinners, to make them saints, to glorify Himself in and by them. With this, too, the Trinity harmonises perfectly: for, instead of its being mere ideas or various functions and displays, the Father in His love gives the Son, who in equal love comes to die, in order righteously to put away sin and to rise in witness of the victory for the believer, and the Holy Spirit deigns to work in the conscience and heart of him who believes, both to convince him of his need and then to fill him with Divine streams of enjoyment and power to magnify Him who died and rose for him.