The virgin birth of Jesus is a crucially important doctrine and one that the Bible plainly teaches in Matthew 1:23 and Luke 1:27, 34.
The virgin birth is important in that it preserves the truth that Jesus is fully God and fully man at the same time.
His physical body He received from Mary as her biological child. But His eternal, holy nature was His from all eternity past (see John 6:69). Jesus had no sin nature (Hebrews 7:26) and therefore was able to be our perfect substitute (1 Peter 1:19), conquering sin and death once for all (Hebrews 10:10).
Not only was He able to take away our sin, but He was tempted in every way that we are, yet without sin. Therefore, He is our perfect sacrifice and also able to empathize with our weaknesses (Hebrews 4:15). Our God miraculously became man to save us and graciously reveal His love for us.
The virgin birth of Jesus is an example of God’s gracious work on our behalf. God took the initiative—Mary was not looking to become pregnant—it was all God’s idea. Joseph had no role in the conception—his body was not involved—so the power had to come from God. In a similar way, our salvation is based solely on God’s initiative and God’s power—we did not seek God, but He sought us; and we did nothing to earn our salvation, but we rely on God’s power.
Unsurprisingly, Jesus’ enemies among His contemporaries denied His virgin birth.
They went so far as to publicly accuse Jesus of being a Samaritan, i.e., a person of mixed race (John 8:48).
Those today who would deny the virgin birth contradict the clear teaching of Scripture, call into question other miracles recorded in the Bible, and open the door to a denial of Christ’s full deity or His full humanity.