The belief among Christian churches nowadays is that God, the Creator of the universe, procreated a Son from eternity. That Son came down and took on a human manifestation in order to redeem people and save them. This belief is wrong, however. It spontaneously falls apart as long as our thinking focuses on the fact that there is one God. To sound reason it is worse than nonsense to think that the one God procreated some Son from eternity and that God the Father together with the Son and the Holy Spirit, each of whom is individually God, together make one God. This fiction completely vanishes like a shooting star in the air when the Word is quoted to show
(a) that Jehovah God himself came down and became human and
(b) that Jehovah God also became the Redeemer.
As for the first point, the following passages show that Jehovah God himself came down and became human:
Behold, a virgin will conceive and bear a Son, who will be called God with us. (Isaiah 7:14; Matthew 1:23)
A Child is born to us; a Son is given to us. Authority will rest on his shoulder, and his name will be called Wonderful, God, Hero, Father of Eternity, Prince of Peace. (Isaiah 9:6)
It will be said in that day, “Behold, this is our God. We have waited for him to free us. This is Jehovah whom we have waited for. Let us rejoice and be glad in his salvation.” (Isaiah 25:9)
The voice of one crying in the desert, “Prepare a way for Jehovah; make a level pathway in the solitude for our God. And all flesh will see it together.” (Isaiah 40:3, 5)
Behold, the Lord Jehovih is coming with strength, and his arm will rule for him. Behold, his reward is with him; like a shepherd he will feed his flock. (Isaiah 40:10–11)
Jehovah said, “Rejoice and be glad, daughter of Zion. Behold, I am coming to live in your midst.” Then many peoples will cling to Jehovah in that day. (Zechariah 2:10–11)
I, Jehovah, have called you in justice; I will give you as a covenant to the people. I am Jehovah. This is my name. I will not give my glory to another. (Isaiah 42:6, 8)
Behold, the days are coming when I will raise up for David a righteous offshoot who will reign as king and execute judgment and justice on the earth. And this is his name: Jehovah our Justice. (Jeremiah 23:5–6; 33:15–16) Then there are the passages where the coming of the Lord is called “the day of Jehovah,” such as Isaiah 13:6, 9, 13, 22; Ezekiel 31:15; Joel 1:15; 2:1, 2, 11, 29, 31; 3:1, 14, 18; Amos 5:13, 18, 20; Zephaniah 1:7–18; Zechariah 14:1, 4–21; and elsewhere.
That Jehovah himself was the one who came down and took on a human manifestation is clearly established in Luke, when it says, “Mary said to the angel, ‘How will this take place, since I have not had intercourse?’ The angel replied to her, ‘The Holy Spirit will descend upon you, and the power of the Highest will cover you; therefore the Holy One that is born from you will be called the Son of God’” (Luke 1:34–35). In Matthew it says that in a dream an angel told Joseph, who was betrothed to Mary, that the child that had been conceived in her was from the Holy Spirit. And Joseph did not have intercourse with her until she gave birth to a Son and called his name Jesus (Matthew 1:20, 25). The “Holy Spirit” means the divine power that radiates from Jehovah God, as we will see in the third chapter of this work [Sections 138–188].
Everyone knows that an offspring’s soul and life come from its father, and the body comes from that soul. To state it very openly, then, the Lord’s soul and life came from Jehovah God; and because divinity cannot be divided, the Lord’s soul and life was the Father’s divinity itself. This is why the Lord frequently called Jehovah God his Father, and Jehovah God called the Lord his Son. What would be more absurd to hear therefore than the idea that the soul of our Lord came from Mary his mother? Yet this is the very thing that both Roman Catholics and Protestants are dreaming today, and they have not been awakened by the Word yet.
from True Christianity, Section 82