"He sent his only son to free us." 

Beloved, now is the acceptable time spoken of by the Spirit, the day of salvation, peace and reconciliation: the great season of Advent.  This is the time eagerly awaited by the patriarchs and prophets, the time that holy Simeon rejoiced at last to see.  This is the season that the Church has always celebrated with special solemnity.  We too should always observe it with faith and love, offering praise and thanksgiving to the Father for the mercy and love he has shown us in this mystery.  In his infinite love for us, though we were sinners, he sent his only son to free us from the tyranny of Satan, to summon us to heaven, to welcome us into its innermost recesses, to show us truth itself, to train us in right conduct, to plant within us the seeds of virtue, to enrich us with the treasures of his grace, and to make us children of God and heirs of eternal life.

 
From a pastoral letter by Saint Charles Borromeo, bishop