There’s a difference between a call (Genesis 12) and a covenant (Genesis 15). A call from God is the Voice of God making a promise to the one who hears. A call of God is a Sovereign statement that the hearer can trust because God is trustworthy. The call is essentially a promise that Abram could and did act upon. It moved him to the promised land and sustained him in the journey and when he arrived. A covenant is something else. A covenant is an oath which is stronger than a promise and if not kept comes with a curse on the oath maker. The difference we in modern times would see is that a call is like a cell phone call setting up an appointment. When we arrive at the appointment, there is a covenant to make. It is a contract with our signatures on it and it becomes a legal document with the weight of the law sustaining all the provisions agreed to in the contract. A covenant by God includes a writing (Genesis 15) witnessed by God and Abram.
15:1 The Introduction. The word of the Lord came to Abram in a vision. We tend to divorce the ideas of “word” and “vision”. Don’t forget that words are the carriers of ideas and ideas are more complex than the words they describe. In fact, words often carry pictures to the mind that accurately describe visions. The adage that “a picture is worth thousand words” has some value but don’t forget that those thousand words are still necessary to describe the picture we are seeking to describe. You can have pictures without words but without words, you don’t know what the picture means!
‘Do not be afraid,’ Abram. I am your shield and your very great reward.”
What was Abram afraid of? The context tells us that he had just won a great victory and honored God by giving a tenth to Melchizedek. But know this, even after a victory there are enemies that remain. Even after giving a tenth, he had deleted his resources. Abram was human wise enough to know that he could not be independent and remain safe. He needed an ally. God says “I will be your ally and I will provide much more than the tenth that you have dispensed.” God claimed to be Abram’s sovereign, thus the shield of protection. God also claimed to be Abram’s inheritance, thus a very great reward which was God rather than just the things of God.
15:2-3 Abram has a complaint.
Abram was not reticent. If God was his sovereign and great reward, what about the real need that Abram had – a posterity? Abram feared that his inheritance would pass on to his servant rather than to his family. Notice that Abram blamed his childless estate on God rather than his wife, Sarah. Children are from the Lord. They are not the “natural fruit of the womb” is people comely think even today. Is not this the deep reason why abortion is sanctioned in society? People look at the results of sexual union as something just physical that has nothing to do with God. Not so. Abram understood this.
15:4-5 God Promises an Overwhelming Number of Children
“Abram, I will give you a son but more. You won’t be able to count the number of children in your family!” In modern times, we still struggle to count the number of stars. If we tried to do a census of the family of Abram, we would struggle just as much.