God has more regard for our intentions than for our accomplishments. Therefore the testing of Abraham was more about his willingness to do what he believed God wanted than about what he might actually do. When the bible was written, human beings could already distinguish abstract concepts like willingness, unconditionally and so on, but they frequently did not yet have the terminology to express these concepts. One very clear example is, of course the parable of the Prodigal Son: the Father welcomed and received his wayward younger son unconditionally. Jesus does not, of course, use the word "unconditional", but rather uses concrete words like "kisses" "gold ring". With our modern consciousness, we can speak of the unconditional love of God for us. The more we read and meditate upon the straightforward story of the Prodigal Son, the more we become capable of understanding the Bible's more problematic stories like that of today's first reading. Did God really demand that Abraham should kill Isaac and make a sacrifice of him? Of course not, and let us not so concentrate on that question that we miss the whole symbolism of the story. Let us say that God wished to put Abraham's trust to the test.