At this point, the author of the Yahwist text describes, in lapidary form, the trusting spirit of Abraham's faith: "He believed the Lord, who credited it to him as righteousness" (v.6). The righteousness and acceptance of God's plan make Abraham the man pleasing to God.
As we have already seen, verse 6 of Gen 15 will be the central argument in Saint Paul (Rom 4, and Gal 3,6f.) to affirm the 'justification' that comes from faith and not from the works of the Law; in other parts of the New Testament, we read that works must be added to faith, as Saint James authoritatively recalls in his letter (2,14 ff.), referring to the same events in Abraham's life: «So also faith without works is dead" (James 2,26:XNUMX). As can be seen throughout the NT, the faith of father Abraham is the model from which to also explain and understand our faith and our following of Jesus, himself a son of Israel.

3. The culmination of Abraham's trusting and obedient faith is described to us, finally, in the mysterious request that God addresses to Abraham to sacrifice his son Isaac, which we find in the chapter. 22 of Genesis.
The text, probably from the Elohist tradition, also wants to indicate that, unlike the human sacrifices celebrated in the Canaanite sanctuaries, any bloody sacrifice of children is prohibited in Israel.
The Fathers of the Church will see in the description of the sacrifice of Isaac, the figure of the sacrifice of Jesus, the only begotten Son.
God wants to test Abraham: he calls him and says to him: «Abraham... Take your son, your only-begotten son, whom you love, Isaac, go to the territory of Mòria and offer him as a burnt offering on a mountain that I will show you» (Gen 22, 2).
The story of Abraham's first call is repeated: God calls, orders to leave, and Abraham obeys.
But here there is no longer the promise of a land and a multitude of peoples as in Gen 12,1 ff.; here the order is the human sacrifice of his son Isaac, long awaited and loved.
V.3 is built on a sequence of dramatic verbs of movement, which barely manage to hide Abraham's anguish: «Abraham rose early in the morning, took with him two servants and his son Isaac, and chopped wood for the burnt offering and set out towards the place that God had indicated to him" (Gen 22,3:XNUMX).
The rest of the story is known to everyone, but it is worth going and rereading it and looking for its meaning to also compare it with our daily existence.
The dialogue between Abraham and his son Isaac (Gen 22,8-10) reaches peaks of great literary power of the dramatic genre: Isaac sees that the fire and the wood are ready but he does not see the lamb of the burnt offering. Abraham replies to his son: "God himself will provide the lamb for the burnt offering" (v.8).
Abraham and his young son set out: but here, Abraham's journey is excruciating and tiring: the promise and the blessings have suddenly vanished, the following of God, who had called him from the pagan world, now appears more than ever absurd: it involves responding to the order of an unspeakable sacrifice that this God asks of him.
This short caravan of people is formed on their way towards a place that God himself wanted to indicate.
They arrive at the place established by God: here, the old father builds the altar, takes the wood, ties young Isaac to it, puts him on the altar and takes the knife to 'immolate his son' (vv.9-10) .
The freshness and crudeness of the intense story today raise doubts and concerns about God's claim towards poor Abraham. But the people of Israel, in the long monotheistic history that will follow, will find, in this story of faith, the rock on which they were able to live and build their unique and privileged relationship with God.
From the faith of Abraham, the forefather of Israel, God will incessantly demonstrate his goodness and tenderness towards the people, as the great biblical prophets will later recall.
At the epilogue of this dramatic story, God, through his angel, intervenes to stop Abraham's arm in the act of sacrificing Isaac: he then recognizes Abraham's radical obedience of his faith (vv. 11-12), and it is renewed the blessing and promise of numerous descendants: «In your descendants all the nations of the earth will be blessed, because you have obeyed my voice» (v.18).
Afterwards we will forever talk about the 'obedience of faith'. Faith is therefore united with the act of obeying: and this seems to us to be incompatible with the goodness of God. We are led to believe that God wants impossible sacrifices from us that cost us dearly.
As experience often tells us, faith is lived 'at a high price', as the great Protestant theologian Bonhoeffer recalled with his evangelical life and martyrdom, but every sacrifice or renunciation is the fruit of an act of love with which God it creates us and sustains us. The 'high price' is the high ideal with which we want to give meaning to our lives, freed from the banalities and indifference of many human lives.
The obedience of faith is then a luminous event for our conscience and for the choices of our life, as were the stories of Francis or Teresa of Calcutta; or as happens in the daily fabric of each of us and our people. In daily faith, even amidst uncertainties and anxieties, we feel the interior presence of the Lord who gives us, in Jesus, the same word once addressed to Abraham, and which makes us understand the profound meaning of our existence.