The evening before Jacob (of the Old Testament) was to meet his brother and attempt a reconciliation, he fell asleep beside a river. Such perfect virtue makes a soul quiet, peaceful, unchanging. This is what our Lord meant by his words, “I leave you peace, my peace I give you.” . . Men who are striving for perfection do not allow themselves to be moved easily by events of the world. They are not afraid whatever trouble comes their way. They are not constantly paralyzed with worry; they meet pain with courage. With their feet firmly planted on the shore, they watch without fear as the waves of human storms arise. It is Christ who gives this steadfastness to Christian souls. . .It was in this way that Jacob, who had cleansed his heart of resentment and so was a man of peace, went ahead of his family to be alone; it was then that he wrestled with God. And the truth is that everyone who frees themselves from worldly things draws near to the likeness and image of God. And this struggle with God means nothing less than to strive for perfection; to encounter Him who is so much greater than ourselves is to gain a unique likeness to the Lord.
– St. Ambrose