Last time we looked at Sabellianism (or, as some know it today, the Oneness view), it's definition and errors through the eyes and pen of B.B. Warfield. Today, let's have a closer inspection of the Trinity from the late Robert Shaw. From his exposition on chapter 2 of the Westminster Confession dealing with the Trinity, he wrote
Before proceeding to establish the doctrine, we must explain the terms employed. The word Godhead signifies the divine nature. This is a scriptural term.–Rom. i. 20; Col. ii. 9. In the Scriptures, and, agreeably to them, in our Confession, Godhead denotes that infinite, eternal, and unchangeable nature, or essence, which is not peculiar to the Father, or the Son, or the Holy Ghost, but common to all the three. The distinction in the Godhead is characterised by the word person. ...When we say that there are three persons in the Godhead, the word person signifies a distinction which we do not pretend to explain, but which does not intrench upon the unity of essence."
There are many passages in the Old Testament which prove a plurality of persons in the Godhead, such as those passages in which one divine person is introduced as speaking of or to another. To these we can only refer.–Gen. i. 26, iii. 22, xi. 7; Ps. xiv. 6, 7, cx. 1; Isa. vi. 8. All these texts plainly point out a plurality of persons in the Godhead. But it is evident from Scripture, not only that there is a plurality, but also that there is a Trinity, or only three persons in the Godhead. This is plain from Isa. lxi. 1, where our Divine Redeemer thus speaks: The Spirit of the Lord God is upon me; because the Lord hath anointed me," &c.
In the New Testament he finds that in, Lord's baptism we have a plain intimation of the mystery of the Trinity.–Matt. iii. 16, 17. The Father, by an audible voice from heaven, bears testimony to the incarnate Redeemer; the Son, in human nature, is baptised by John; and the Holy Spirit: descends upon him in a visible manner. Hence the primitive Christians used to say to any who doubted the truth of this doctrine, "Go to Jordan, and there you will see the Trinity." Plainer still is this truth from the form of words appointed to be used in Christian baptism,–"Baptising them in the name of the Father, and of the Son, and of the Holy Ghost." - Matt. xvi. 19. To baptise in the name of one, is to baptise by his authority, and dedicate to his service. This is competent only to a divine person. Now, if the Father, in whose name we are baptised, be a person, so must the Son, and the Holy Ghost, for we are baptised in their name, as well as in the name of the Father. The apostolic benediction furnishes another proof of a Trinity: "The grace of our Lord Jesus Christ, the love of God, and the communion of the Holy Ghost, be with you all."–2 Cor. xiii. 14. "This is evidently a prayer, which it would be impiety and idolatry to address to any other but God. Yet three persons are distinctly addressed, and consequently are recognised as possessed of divine perfections; as knowing our wants, and hearing our requests, and able to do what we ask; as the fountain of all the blessedness implied in the terms, grace, love, and communion." We have a most explicit testimony to this doctrine, 1 John. v. 7, "There are three that bear record in heaven, the Father, the Word, and the Holy Ghost, and these three are one."
And here, Shaw addresses the crux of the matter
Nor is the doctrine of the Trinity a mere-speculation. On the contrary, to use the language of Dr Dick, "without the knowledge of this doctrine it is impossible to understand the grandest of the works of God–redemption,–in which the three persons act distinct and conspicuous parts. We are called to contemplate the love of the Father, the condescension of the Son, and the gracious operations of the Spirit. Redemption is not the work of a solitary agent, but of three, all concurring in the salvation of our perishing race. Hence we owe gratitude to each of the persons of the Godhead distinctly, and are bound to give to each the glory to which he is entitled. We are baptised in their name, and consecrated to their service; and our prayers are addressed not to God absolutely considered, but to the Father, through the Son, and by the assistance of the Holy Ghost. It appears, therefore, that the Christian system of duty is founded upon this doctrine, and that without the belief of it there can be no acceptable religion. So far is it from being useless, that it is the very foundation of practical piety." Shaw, Robert; Charles River Editors; Hetherington, WM M. (2011-09-11). The Reformed Faith: An Exposition of the Westminster Confession of Faith (Kindle Locations 1076-1125). Unknown. Kindle Edition.
Therefore, in it's relation to redemption, a critical knowledge and acceptance of the doctrine of the Trinity is paramount. This is why the the Elephant Room discussion between Driscoll and Jakes has drawn so much attention and rightfully so. If Jakes espouses something other than the doctrine of the Trinity as found in the Westminster Confession and explained briefly above (manifestations vs. persons), he is not preaching the true Gospel of Christ found in the Scriptures and misleading a great many souls astray.
For a more thorough review if this issue, check out this post at the Gospel Coalition. And, if someone is still saying, "What's the big deal?," take a look at this.