In Part 1, I reblogged an article which quoted from Dr. John Frame. (The article is by Andreas Köstenberger and Alexander Stewart, who began with a quote from Dr. John Frame). See the quote below. I would add to those 5 crucial doctrines, that the virgin birth of Christ is also doctrinally important to the atonement of Christ. Hebrews 2:14-17 demonstrates this, “it was necessary” for the eternal Son to become human, in order to be the atonement and make the offering of the atonement as a faithful and merciful high priest.
“It was necessary for Him to made like His brethren in all things [human, taking on a full humanity; the virgin Birth of Christ, the incarnation, becoming flesh and blood], in order that He might become a merciful and faithful high priest [both the sacrifice and the sacrificer] in things pertaining to God, to make propitiation [the satisfaction for God’s justice and wrath against sin] for the sins of the people.” Hebrews 2:17 (with my emphasis and comments)
Meditating on the Incarnation of Christ and the Virgin Birth of Christ is such a great blessing and part of “cultivating faithfulness” (Psalm 37:3) – John 1:1-5; 1:14-18; Matthew chapters 1-2; Luke chapters 1-2; Hebrews 2:14-18; Philippians 2:5-11; Colossians 1:15-20; Hebrews chapter 1. Together, the purpose of the Incarnation points to the Atonement (Propitiation for sin) and the Resurrection of the Messiah from the dead, proves and empowers these 2 truths. This is also the argument that Athanasius made sometime after he became bishop of Alexandria, around 328 AD when he wrote his famous book, “The Incarnation of the Word”, in defending the doctrine of the Deity of Christ and the Council of Nicea in 325 AD.
So why is the virgin birth theologically important? John Frame helpfully summarizes the main reasons:
The virgin birth is doctrinally important because of: (1) The doctrine of Scripture. If Scripture errs here, then why should we trust its claims about other supernatural events, such as the resurrection? (2) The deity of Christ. While we cannot say dogmatically that God could enter the world only through a virgin birth, surely the incarnation is a supernatural event if it is anything. To eliminate the supernatural from this event is inevitably to compromise the divine dimension of it. (3) The humanity of Christ. This was the important thing to Ignatius and the second century fathers. Jesus was really born; he really became one of us. (4) The sinlessness of Christ. If he were born of two human parents, it is very difficult to conceive how he could have been exempted from the guilt of Adam’s sin and become a new head to the human race. And it would seem only an arbitrary act of God that Jesus could be born without a sinful nature. Yet Jesus’ sinlessness as the new head of the human race and as the atoning lamb of God is absolutely vital to our salvation (Rom. 5:18–19; 2 Cor. 5:21; Heb. 4:15; 7:26; 1 Pet. 2:22–24). (5) The nature of grace. The birth of Christ, in which the initiative and power are all of God, is an apt picture of God’s saving grace in general of which it is a part. It teaches us that salvation is by God’s act, not our human effort. 
We have to remember to keep focusing on the Lord (meditate on Who He is – on the glorious splendor of Your Majesty, I will meditate – Psalm 145:5), even though life in this world is difficult and civilization is being destroyed by secularists / atheists / intersectionality, LGBTQ political agenda, abortionists (murderers of babies), Socialists, Marxists, and violence in the cities. Psalm 37:1-11 Our Pastor, Ty Blackburn, recently preached on this passage and gave really good insight – verse 3 – “Dwell in the land and cultivate faithfulness” = feed on God’s faithfulness; mediate in the Word on who God is and His attributes. (Google for his sermon: “The Christian’s Warfare: A Biblical Perspective on Victory, Pastor Ty Blackburn, Providence Church, Duluth, Ga.)