The Heart Of Christmas: God keeps His promises.

In His faithfulness, God protects us from evil (2 Thessalonians 3:3), sets limits on our temptations (1 Corinthians 10:13), forgives us of sin (1 John 1:9), and sanctifies us (1 Corinthians 1:9; Philippians 1:6).
Promise of the Virgin Birth
God stood by his promise to Ahaz that the two nations menacing him would fall. But Ahaz’s unbelief was costly. His crisis was resolved by a more terrible enemy, the king of Assyria himself (7:15–17). Someone has said that this whole episode was like a mouse attacked by two rats, squeaking for the cat to come save him. The cat did (2 Kings 16:5–9). But the mouse ended up as dessert.
Most Christians accepted the Virgin Birth without hesitation until liberal theology challenged miracles in the nineteenth century. Then it became a pivotal point in the debate about Christian supernaturalism and the divinity of Jesus.
Liberalism, seeking to desupernaturalize the faith and reinterpret Jesus as no more than a uniquely godly and insightful teacher, surrounded the Virgin Birth with a spirit of needless and unreasonable skepticism.