James 2:23

‘And the scripture was fulfilled which says, “And Abraham believed God, and it was reckoned to him for righteousness”, and he was called the friend of God.'

So Abraham's action in offering Isaac  in obedience to God's command  brought to completeness (fulfilled) his action of earlier believing in God and His promises, and thus being reckoned as righteous. It demonstrated to Heaven and earth that it was true that he really was righteous, and had become so those many years before when he believed. His action in offering Isaac had not made him righteous. It had simply demonstrated that he was righteous. It had capped many years of faithful response. Once Isaac had been delivered no one could ever again be in doubt about the fact that he was the friend of God, one on whom God smiled, and one who loved God, and it had all been made apparent because of his actions, his ‘works'.

For ‘the friend of God' see 2 Chronicles 20:7, ‘did you not give -- this land for ever to Abraham your friend?' Notice there that this demonstrates that he was called the friend of God on the basis of Genesis 15:18 where he was promised the land, and not on the basis of Genesis 22, where he was not promised the land. Again in Isaiah 41:8 Abraham is seen as Abraham's friend, but in that case it was because he was specially chosen. Thus Abraham became God's friend, first because he was chosen, and then because he believed God. His works simply proved that he recognised Him as his friend.

We can compare here the many who came to Jesus and said that they believed, and that they accepted Him as their Lord, and then went away smugly satisfied but unchanged. They felt that they had done their bit and that Jesus should be grateful. But Jesus said of them, ‘not every one who says to me ‘Lord, Lord' will enter under the Kingly Rule of God, but only those who do the will of My Father Who is in Heaven' (Matthew 7:21). For how can we be said to have entered under the Kingly Rule of God if we do not do His will? And how can we be said to have been ‘saved' (‘made whole') if we have in fact become no different? If we have become no different then the truth is that God has passed us by. But if that is so it is our fault not His.