Now Adonai said to Avram, “Get yourself out of your country, away from your kinsmen and away from your father’s house, and go to the land that I will show you. I will make of you a great nation, I will bless you, and I will make your name great; and you are to be a blessing. I will bless those who bless you, but I will curse anyone who curses you; and by you all the families of the earth will be blessed." (Bereshit / Genesis 12:1-3; CJB)
The call of Avram (English: Abram) is the beginning of the unfolding of God's earlier promise to destroy evil in the world (see Bereshit / Genesis 3:15). Against the backdrop of the building of the city and tower of Babel (see Bereshit / Genesis 11:1-9), when God thwarted the people's attempt to find unity, security, and greatness in themselves and their own plans and effort, God promised blessing for the whole world through Avram and his descendants.
The word for blessing in Hebrew is "barach", which means to fill something with the potential of life. When something is blessed, it not only has life itself, but produces life that produces life. Healthy trees bear fruit with seeds that result in trees that bear fruit with seeds and so on. Barach is the opposite of arar "cursing", the removal of life. A land that is cursed is dead and produces nothing.
The promise to Avram to be a blessing to the nations is God's remedy for the curse pronounced on creation in the Garden of Eden. The consequences of our first parents' rebellion against God would be undone through the blessing that was to be extended to all families of the earth through Avram's descendants, the people of Israel.
As the story of God progresses through the pages of the Tenach (Hebrew Scriptures or Old Testament), we discover that the way Israel will bring God's blessing to the world comes to its fullness through the Messiah. This is why in the New Covenant Scriptures, Paul calls God's promise to Avram the Good News (see Galatians 3:8). It is because of the coming of the Messiah that the reality of the God of Israel has come to the whole world.
To fully appreciate the nature of the blessing that is now available to all people everywhere, we need to reflect upon who it was to whom the promise of blessing was given: an elderly childless man. Avram and his wife could not have children. They were already 75 and 65 respectively when Avram first received the promise. It would be twenty five more years before Isaac is born.
What makes God's blessing so remarkable is that it brings reproducible life where there was nothing before. God promised a great nation to a man who could not have children. This means Avram's ability to achieve God's plan for his life was in no way contingent upon his ability or resources. It was solely dependent upon God's word.
Followers of the Messiah have been made part of God's promise to Avram. We are not only recipients of the blessing; we are called, like Avram, to be carriers of it to others. Like Avram we need not be concerned about whether or not we think we have what it takes. In fact, we should not be surprised if God wants to bless others through areas of our lives where we seem the weakest.