The work of Jesus Christ was to birth God’s true family and to bring about the true eternal order of God, which is the order of grace. He came to establish the new covenant (he fulfilled the old so that he could establish the new) (John 1:17). The true family of God begins with Jesus Christ. This is the family of sons and daughters, not that of servants. God has always wanted a family that would walk with him by faith and that is ruled by His Spirit. He wanted a family that He could function with through grace. This is called the true family of God because God birthed it Himself through Christ. When we receive Jesus Christ, God through his Spirit births us and we are given his nature (John 1:12), therefore we are able to do his will from our hearts because we have his nature (Hebrews 8:10-12). So then, we who have received Jesus Christ, we are the ones who are the true children of Abraham by faith, and we are heirs according to the promise (Galatians 3:26).
THE LINK BETWEEN GOD’S COVENANT WITH ABRAHAM AND GOD’S COVENANT WITH JESUS CHRIST.
This covenant that God made with Abraham, is linked with this new covenant, which is between Jesus and God in a sense that the covenant between God and Abraham was to make him the father of faith to all those who are the true family of God. The covenant between God and Jesus was to start the true family of God who are children of Abraham in faith; this is why the bible calls us his descendants and also says that his blessings are ours and that we walk in his footsteps of faith.
Example, in the new covenant we give our tithes to God because it is the principle of our covenant with God, not because we are under the Law of Moses. This is what Abraham did when he revered God and acknowledged Gods greatness in his life. We believe and we confess because Abraham believed what God said about him and called himself what God called him, he ignored the physical signs of the absence of a child when he called himself the father of many nations (Romans 4:17-25).