A Voice from the Past - Leo the Great

For not only is God believed to be both Almighty and the Father, but the Son is shown to be co-eternal with Him, differing in nothing from the Father because He is God from God, Almighty from Almighty, and being born from the Eternal one is co-eternal with Him; not later in point in time, not lower in power, not unlike in glory, not divided in essence; but at the same time the only begotten of the eternal Father was born eternal of the Holy Spirit and the Virgin Mary. And this nativity which took place in time took nothing from, and added nothing to that divine and eternal birth, but expended itself wholly on the restoration of man who had been deceived; in order that he might both vanquish death and overthrow by his strength, the Devil who possessed the power of death. For we should not now be able to overcome the author of sin and death  unless He took our nature on Him and made it His own, whom neither sin could pollute nor death retain.

Leo the Great, 400-460 AD, Letter 28, To Flavian, commonly called "The Tome," Section II (The Nicene and Post-Nicene Fathers, Volume 12, Philip Schaff and Henry Wace, 1997, T & T Clark and Wm. B.Eerdmans, The Letters and Sermons of Leo the Great, translated by Charles Lett Feltoe, p. 39)

Why is it important that Jesus was both God and man? What impact does this have on our lives?