I will preface this by noting that I think that any answer to this question is speculative; it’s not something directly addressed by scripture and left for us to ponder. But it is an interesting question.
The best answer that I have found for this is rooted both in Judaism and the Early Church. Namely: by identifying the Son with the Light created on the first day, and as the Wisdom of God in Proverbs 8. The light and wisdom are one and the same. “Us” then both includes Christ and does so without any need to reference the non-biblical concept of the Trinity.
Within Judaism, the first light has long been associated with the Messiah. For example, see Yalkut Shimoni 499:
“Before the world was created, Hashem created the soul of Moshiach. It
shone very brightly, and is hinted to in the verse: “And Hashem saw
the light, that it was good.” The forces of evil also saw this light,
and asked Hashem, “Whose light is this?” Hashem answered, “This is the
king who will defeat all of you in the End of Days.” The forces of
evil then fell on the ground in fear before the soul of Moshiach.
Hashem then asked Moshiach, “It is destined that you will suffer
greatly. Are you willing to accept this suffering?” Moshiach answered,
“If you agree that in the Days of Moshiach everyone will live again
and even those who were meant to be born will come to life — upon
these conditions I happily accept the suffering.” And when the time
for Redemption comes, Avraham, Yitzchak and Yaakov will come to
Moshiach and say, “Perhaps you have bad feeling towards the Jews who
sinned, and therefore caused you to suffer. Maybe you don’t want them
to have a share in the joys of Geulah?” And Moshiach will answer them,
“But all my suffering was only for their sake! Of course I want them
to have a share in the Geulah!” And our Avos will answer him,
“Moshiach, you have comforted us!”
Likewise, many of the Early Church Fathers identified the Son as the Wisdom of God in Proverbs 8. For example, Justin Martyr quotes/paraphrases Proverbs 8 in chapter 61 of his Dialogue with Trypho:
“I shall give you another testimony, my friends,” said I, “from the
Scriptures, that God begat before all creatures a Beginning, [who was]
a certain rational power [proceeding] from Himself, who is called by
the Holy Spirit, now the Glory of the Lord, now the Son, again Wisdom,
again an Angel, then God, and then Lord and Logos; and on another
occasion He calls Himself Captain, when He appeared in human form to
Joshua the son of Nave (Nun). For He can be called by all those names,
since He ministers to the Father’s will, and since He was begotten of
the Father by an act of will; just as we see happening among
ourselves: for when we give out some word, we beget the word; yet not
by abscission, so as to lessen the word [which remains] in us, when we
give it out: and just as we see also happening in the case of a fire,
which is not lessened when it has kindled [another], but remains the
same; and that which has been kindled by it likewise appears to exist
by itself, not diminishing that from which it was kindled. The Word of
Wisdom, who is Himself this God begotten of the Father of all things,
and Word, and Wisdom, and Power, and the Glory of the Begetter, will
bear evidence to me, when He speaks by Solomon the following: ‘If I
shall declare to you what happens daily, I shall call to mind events
from everlasting, and review them. The Lord made me the beginning of
His ways for His works. From everlasting He established me in the
beginning, before He had made the earth, and before He had made the
deeps, before the springs of the waters had issued forth, before the
mountains had been established. Before all the hills He begets me. God
made the country, and the desert, and the highest inhabited places
under the sky. When He made ready the heavens, I was along with Him,
and when He set up His throne on the winds: when He made the high
clouds strong, and the springs of the deep safe, when He made the
foundations of the earth, I was with Him arranging. I was that in
which He rejoiced; daily and at all times I delighted in His
countenance, because He delighted in the finishing of the habitable
world, and delighted in the sons of men. Now, therefore, O son, hear
me. Blessed is the man who shall listen to me, and the mortal who
shall keep my ways, watching daily at my doors, observing the posts of
my ingoings. For my outgoings are the outgoings of life, and [my] will
has been prepared by the Lord. But they who sin against me, trespass
against their own souls; and they who hate me love death.’
Within scripture itself, Jesus is referred to as Light and as the Wisdom of God:
John 1:3-4
In him was life, and that life was the light of all mankind. 5 The
light shines in the darkness, and the darkness has not overcome it.
John 1:9
The true light that gives light to everyone was coming into the world.
John 8:12
When Jesus spoke again to the people, he said, “I am the light of the
world. Whoever follows me will never walk in darkness, but will have
the light of life.”
John 12:36
Believe in the light while you have the light, so that you may become
children of light.” When he had finished speaking, Jesus left and hid
himself from them.
Revelation 21:23-24
The city does not need the sun or the moon to shine on it, for the
glory of God gives it light, and the Lamb is its lamp. The nations
will walk by its light, and the kings of the earth will bring their
splendor into it.
1 Corinthians 1:23-24
but we preach Christ crucified: a stumbling block to Jews and
foolishness to Gentiles, 24 but to those whom God has called, both
Jews and Greeks, Christ the power of God and the wisdom of God.
So then, Christ is the light and wisdom of God - the first of creation. He was present with God in the beginning and it was through him, God’s wisdom, that all else was created.
