St. Leo the Great (400-461) was the Bishop of Rome. One of his major accomplishments was dissuading Atilla the Hun from invading Italy. He is also considered by Roman Catholics to be a Doctor of the Church and was an important rhetorical combatant against a number of heretics.
In his Sermon 22.5, he discusses the benefits of the Incarnation and Atonement for the Christian. Here is what he says (emphasis added):
Whoever you are, if you devoutly and faithfully boast in the name of Christian, value this atonement rightly. You were a castaway, banished from the realms of paradise, dying of your weary exile, reduced to dust and ashes, with no more hope of living. But by the incarnation of the Word, you were given power to return from far away to your Maker, to recognize your parentage, to be free when you had been a slave, to be promoted from an outcast to a son. Now you, who were born of the flesh, may be reborn by the Spirit of God. You may gain by grace what you did not have by nature, and--if you acknowledge yourself as the child of God by the spirit of adoption--you may dare to call God Father.Leo sees that Christ's Incarnation and death provides the means for God to make the first move towards us. Yet, according to Leo, this is a possibility, not an inevitable reality. One may not accept the gift but God gives us the ability to.