The Heidelberg Catechism Part II: Deliverance God the Son, Part 4 Lord’s Day 14
Question 35: What does it mean that He “was conceived by the Holy Spirit and born of the virgin Mary”?
Answer 35: That the eternal Son of God, who is and remains true and eternal God,  took to Himself, through the working of the Holy Spirit,  from the flesh and blood of the virgin Mary,  a truly human nature so that He might also become David’s true descendant,  like His brothers and sisters in every way  except for sin. ]6]
Supporting Scripture:  John 1:1 NKJV In the beginning was the Word, and the Word was with God, and the Word was God.
John 10:30-36 NKJV I and My Father are one." (31) Then the Jews took up stones again to stone Him. (32) Jesus answered them, "Many good works I have shown you from My Father. For which of those works do you stone Me?" (33) The Jews answered Him, saying, "For a good work we do not stone You, but for blasphemy, and because You, being a Man, make Yourself God." (34) Jesus answered them, "Is it not written in your law, 'I said, "you are gods" '? (35) If He called them gods, to whom the word of God came (and the Scripture cannot be broken), (36) do you say of Him whom the Father sanctified and sent into the world, 'You are blaspheming,' because I said, 'I am the Son of God'?
Acts 13:33 NKJV (Ps. 2:7) God has fulfilled this for us their children, in that He has raised up Jesus. As it is also written in the second Psalm: 'You are My Son, today have I begotten You.'
Colossians 1:15-17 NKJV He is the image of the invisible God, the firstborn over all creation. (16) For by Him all things were created that are in heaven and that are on earth, visible and invisible, whether thrones or dominions or principalities or powers. All things were created through Him and for Him. (17) And He is before all things, and in Him all things consist.
1 John 5:20 NKJV And we know that the Son of God has come and has given us an understanding, that we may know Him who is true; and we are in Him who is true, in His Son Jesus Christ. This is the true God and eternal life.
 Luke 1:35 NKJV And the angel answered and said to her, "The Holy Spirit will come upon you, and the power of the Highest will overshadow you; therefore, also, that Holy One who is to be born will be called the Son of God.
 Matthew 1:18-23 NKJV Now the birth of Jesus Christ was as follows: After His mother Mary was betrothed to Joseph, before they came together, she was found with child of the Holy Spirit. (19) Then Joseph her husband, being a just man, and not wanting to make her a public example, was minded to put her away secretly. (20) But while he thought about these things, behold, an angel of the Lord appeared to him in a dream, saying, "Joseph, son of David, do not be afraid to take to you Mary your wife, for that which is conceived in her is of the Holy Spirit. (21) And she will bring forth a Son, and you shall call His name JESUS, for He will save His people from their sins." (22) So all this was done that it might be fulfilled which was spoken by the Lord through the prophet, saying: (23) "Behold, the virgin shall be with child, and bear a son, and they shall call His name Immanuel," which is translated, "God with us."
John 1:14 NKJV And the Word became flesh and dwelt among us, and we beheld His glory, the glory as of the only begotten of the Father, full of grace and truth.
Galatians 4:4 NKJV But when the fullness of the time had come, God sent forth His Son, born of a woman, born under the law,
Hebrews 2:14 NKJV Inasmuch then as the children have partaken of flesh and blood, He Himself likewise shared in the same, that through death He might destroy him who had the power of death, that is, the devil,
 2 Samuel 7:12-16 NKJV "When your days are fulfilled and you rest with your fathers, I will set up your seed after you, who will come from your body, and I will establish his kingdom. (13) He shall build a house for My name, and I will establish the throne of his kingdom forever. (14) I will be his Father, and he shall be My son. If he commits iniquity, I will chasten him with the rod of men and with the blows of the sons of men. (15) But My mercy shall not depart from him, as I took it from Saul, whom I removed from before you. (16) And your house and your kingdom shall be established forever before you. Your throne shall be established forever." ' "
Psalms 132:11 NKJV The LORD has sworn in truth to David; He will not turn from it: "I will set upon your throne the fruit of your body.
Matthew 1:1 NKJV The book of the genealogy of Jesus Christ, the Son of David, the Son of Abraham:
Romans 1:3 NKJV concerning His Son Jesus Christ our Lord, who was born of the seed of David according to the flesh,
 Philippians 2:7 NKJV but made Himself of no reputation, taking the form of a bondservant, and coming in the likeness of men.
Hebrews 2:17 NKJV Therefore, in all things He had to be made like His brethren, that He might be a merciful and faithful High Priest in things pertaining to God, to make propitiation for the sins of the people.
 Hebrews 4:15 NKJV For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin.
Hebrews 7:26-27 NKJV For such a High Priest was fitting for us, who is holy, harmless, undefiled, separate from sinners, and has become higher than the heavens; (27) who does not need daily, as those high priests, to offer up sacrifices, first for His own sins and then for the people's, for this He did once for all when He offered up Himself.
Q36: How does the holy conception and birth of Christ benefit you?
A36: He is our mediator  and, in God’s sight, He covers with His innocence and perfect holiness my sinfulness in which I was conceived. 
 1 Tim. 2: 1 Timothy 2:5-6 NKJV For there is one God and one Mediator between God and men, the Man Christ Jesus, (6) who gave Himself a ransom for all, to be testified in due time,5-6;
Hebrews 9:13-15 NKJV For if the blood of bulls and goats and the ashes of a heifer, sprinkling the unclean, sanctifies for the purifying of the flesh, (14) how much more shall the blood of Christ, who through the eternal Spirit offered Himself without spot to God, cleanse your conscience from dead works to serve the living God? (15) And for this reason He is the Mediator of the new covenant, by means of death, for the redemption of the transgressions under the first covenant, that those who are called may receive the promise of the eternal inheritance.
 Romans 8:3-4 NKJV For what the law could not do in that it was weak through the flesh, God did by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh, (4) that the righteous requirement of the law might be fulfilled in us who do not walk according to the flesh but according to the Spirit.
2 Corinthians 5:21 NKJV For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him.
Galatians 4:4-5 NKJV But when the fullness of the time had come, God sent forth His Son, born of a woman, born under the law, (5) to redeem those who were under the law, that we might receive the adoption as sons.
1 Peter 1:18-19 NKJV knowing that you were not redeemed with corruptible things, like silver or gold, from your aimless conduct received by tradition from your fathers, (19) but with the precious blood of Christ, as of a lamb without blemish and without spot.