It is not unbiblical at all, CS1. I will provide the Scripture that affirms that they both came into time:
Luke 2:8-14 King James Bible
And there were in the same country shepherds abiding in the field, keeping watch over their flock by night.
{9} And, lo, the angel of the Lord came upon them, and the glory of the Lord shone round about them: and they were sore afraid.
{10} And the angel said unto them, Fear not: for, behold, I bring you good tidings of great joy, which shall be to all people.
{11} For unto you is
born this day in the city of David
a Saviour, which is Christ the Lord. {12} And this
shall be a sign unto you; Ye shall find the babe wrapped in swaddling clothes, lying in a manger.
{13} And suddenly there was with the angel a multitude of the heavenly host praising God, and saying,
{14} Glory to God in the highest, and on earth peace, good will toward men.
In the above Scripture, we see here that Christ the Lord was born into this world, and hence, He came from Eternity into time.
Let’s look at another Scripture which affirms this truth:
John 7:21-44 King James Bible
Jesus answered and said unto them, I have done one work, and ye all marvel.
{22} Moses therefore gave unto you circumcision; (not because it is of Moses, but of the fathers
and ye on the sabbath day circumcise a man.
{23} If a man on the sabbath day receive circumcision, that the law of Moses should not be broken; are ye angry at me, because I have made a man every whit whole on the sabbath day?
{24} Judge not according to the appearance, but judge righteous judgment.
{25} Then said some of them of Jerusalem, Is not this he, whom they seek to kill?
{26} But, lo, he speaketh boldly, and they say nothing unto him. Do the rulers know indeed that this is the very Christ?
{27} Howbeit we know this man whence he is: but when Christ cometh, no man knoweth whence he is.
{28} Then cried Jesus in the temple as he taught, saying, Ye both know me, and ye know whence I am: and I am not come of myself, but he that sent me is true, whom ye know not.
{29} But I know him:
for I am from him, and he hath sent me. {30} Then they sought to take him: but no man laid hands on him, because his hour was not yet come.
{31} And many of the people believed on him, and said, When Christ cometh, will he do more miracles than these which this
man hath done?
{32} ¶ The Pharisees heard that the people murmured such things concerning him; and the Pharisees and the chief priests sent officers to take him.
{33} Then said Jesus unto them, Yet a little while am I with you, and
then I go unto him that sent me.
{34} Ye shall seek me, and shall not find
me: and where I am,
thither ye cannot come.
{35} Then said the Jews among themselves, Whither will he go, that we shall not find him? will he go unto the dispersed among the Gentiles, and teach the Gentiles?
{36} What
manner of saying is this that he said, Ye shall seek me, and shall not find
me: and where I am,
thither ye cannot come?
{37} In the last day, that great
day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink.
{38} He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water.
{39} (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet
given; because that Jesus was not yet glorified.)
{40} ¶ Many of the people therefore, when they heard this saying, said, Of a truth this is the Prophet.
{41} Others said, This is the Christ. But some said, Shall Christ come out of Galilee?
{42} Hath not the scripture said, That Christ cometh of the seed of David, and out of the town of Bethlehem, where David was?
{43} So there was a division among the people because of him.
{44} And some of them would have taken him; but no man laid hands on him."
And so now that we have seen Scripture that affirms that Christ Jesus came into time as a seed. Now let’s look at Scripture which doth affirm that Jesus also grew unto perfection over time:
Luke 2:46-52 King James Bible
And it came to pass, that after three days they found him in the temple, sitting in the midst of the doctors, both hearing them, and asking them questions.
{47} And all that heard him were astonished at his understanding and answers.
{48} And when they saw him, they were amazed: and his mother said unto him, Son, why hast thou thus dealt with us? behold, thy father and I have sought thee sorrowing.
{49} And he said unto them, How is it that ye sought me? wist ye not that I must be about my Father’s business?
{50} And they understood not the saying which he spake unto them.
{51} And he went down with them, and came to Nazareth, and was subject unto them: but his mother kept all these sayings in her heart.
{52} And Jesus increased in wisdom and stature, and in favour with God and man."
Luke 2:34-40 King James Bible
And Simeon blessed them, and said unto Mary his mother, Behold, this
child is set for the fall and rising again of many in Israel; and for a sign which shall be spoken against;
{35} (Yea, a sword shall pierce through thy own soul also,) that the thoughts of many hearts may be revealed.
{36} And there was one Anna, a prophetess, the daughter of Phanuel, of the tribe of Aser: she was of a great age, and had lived with an husband seven years from her virginity;
{37} And she
was a widow of about fourscore and four years, which departed not from the temple, but served
God with fastings and prayers night and day.
{38} And she coming in that instant gave thanks likewise unto the Lord, and spake of him to all them that looked for redemption in Jerusalem.
{39} And when they had performed all things according to the law of the Lord, they returned into Galilee, to their own city Nazareth.
{40} And the child grew, and waxed strong in spirit, filled with wisdom: and the grace of God was upon him."
Notice CS1, that the above Scripture clearly says that the child (Jesus) grew and waxed strong in spirit. Let’s look at another Scripture though concerning Jesus’ growth and maturity unto perfection:
Hebrews 5:5-10 King James Bible
So also Christ glorified not himself to be made an high priest; but he that said unto him, Thou art my Son, to day have I begotten thee. As he saith also in another [place], Thou [art] a priest for ever after the order of Melchisedec. Who in the days of his flesh, when he had offered up prayers and supplications with strong crying and tears unto him that was able to save him from death, and was heard in that he feared;
Though he were a Son, yet learned he obedience by the things which he suffered; And being made perfect, he became the author of eternal salvation unto all them that obey him; Called of God an high priest after the order of Melchisedec.
CS1, how much clearer can that Holy Scripture be?