Duty of Believing in Jesus Christ: States of Christ: Original Glory- Book Fifth- Chapter 2- Section 1
STATES OF CHRIST.
SECTION 1.–ORIGINAL GLORY.
BEFORE HIS INCARNATION, THE SON OF GOD WAS IN INTIMATE COMMUNION OF GLORY AND BLESSEDNESS WITH THE FATHER.
The existence of Christ, previous to his appearing in the world, is proved by passages of Scripture, that do not expressly declare his divinity.
If we had no further teaching on the subject, we might suppose that he was a created spirit, had enjoyed honor and happiness in the presence of God, and had consented to appear, in obedience to the will of God, in the person of Jesus Christ. But the proofs which have been adduced from other parts of Scripture, clearly show that this pre-existent spirit was God, and not a creature.
Several names are ascribed to the pre-existent divinity of Jesus Christ. John calls him the Word of God. He is more frequently called the Son of God. Various passages speak of him as the Son of God, antecedent to his coming into the world. He is called the Angel of the Lord, the Angel of the Lord’s presence, the Angel of the Covenant, the Captain of the Lord’s hosts. It is also supposed that he is intended to be designated, in the 8th chapter of Proverbs, by the name Wisdom.
To ascertain the precise import of these several names, is attended with difficulty. He appears to be called the Angel or Messenger, because he is sent to make known, or to execute, the will of God. He is probably called the Word of God, because he is the medium through which the mind of God is made known. Why he is called the Son of God, is a question on which divines have differed. His miraculous conception, his mediatorial office, his resurrection from the dead, and his investiture with supreme dominion, have been severally assigned, as the reason of the title; but these appear rather to declare him to be the Son of God, or to belong to him because of that relation, than to constitute it. The phrases first-born, first-begotten, only-begotten, seem to refer to the true ground of the name, Son of God: but what these signify, it is probably impossible for us to understand. The ideas of peculiar endearment, dignity, and heirship, which are attached to these terms, as used among men, may be supposed to belong to them, as applied to the Son of God; but all gross conceptions of their import, as if they were designed to convey to our minds the idea of derived existence, and the mode of that derivation, ought to be discarded as inconsistent with the perfection of Godhead. Some have considered the titles Christ, the Son of God, as equal and convertible; but the distinction in the use of them, as pointed out in our examination of the charges brought against the Redeemer, shows the error of this opinion. When Saul at Damascus, and Apollos in Achaia, preached to the Jews that Jesus was the Christ, the aim was to convince them that Jesus was the Messiah, long expected by their nation. But when Saul preached “Christ, that he is the Son of God,” and when the eunuch professed his faith, “I believe that Jesus is the Son of God,” more than the mere messiahship of Jesus is manifestly intended. Christ or Messiah is a title of office: but the phrase “Son of God,” denotes, not the mere office, but the exalted nature which qualified for it.
The possession of proper deity is alone sufficient to show that the Son of God was glorious and happy eternally; but we may learn the same truth from the language of Scripture directly referring to this subject. “And now, O Father, glorify thou me with thine own self, with the glory which I had with thee, before the world was.” “For ye know the grace of the Lord Jesus Christ, that though he was rich, yet for your sakes he became poor, that ye through his poverty might be rich.” “Then I was by him, as one brought up with him; and I was daily his delight, rejoicing always before him.” “Who, being in the form of God, thought it not robbery to be equal with God.” “The only begotten Son, which is in the bosom of the Father.” The full communion of the Son with the Father, in all the glory and blessedness of the Godhead, is to be inferred from these passages.
 John i. 15, 30; iii. 13, 17, 31; vi. 38; viii. 58; xvii. 5; 1 Cor. xv. 47; Gen xvii. xxii. 15; xxxii. 30; Ex. iii. ; xx.; Acts vii. 30, 35, 38; John i. 3; Col. i. 16; Heb. i. 2, 10; Mic. v. 2; John viii. 58; Heb. i. 8; xiii. 8; Rev. i. 8, 18.
 John i. 1.
 Acts ix. 22.
 Acts xviii. 28.
 Acts ix. 20.
 Acts viii. 37.
 John xvii. 5.
 2 Cor. viii. 9.
 Prov. viii. 30.
 Phil. ii. 6.
 John i. 18.
John L. Dagg- Manual of Theology