Something seems awry. The text tells us that Abram believed God, and his belief was accounted to him as righteousness (Genesis 15:6). Then in Genesis 15:8 we are told that Abram asks God, yes, but “how shall I know that I’ll inherit?” Doesn’t this contradict what is said of Abram in verse-6? In a word: “No!” it does not. How can I say this? Well, if we try to honestly explain Abram’s question and at the same time agree that he believed God, then we must conclude that Abram desired an explanation. He believed, but he didn’t understand. The same Hebrew word translated “shall I know” in the KJV is translated teach five times and showed another five times in Scripture.
Abram was being honest, saying to God that he believed him, but he didn’t understand how this could ever come about if he (Abram) couldn’t do his part in producing an heir for God to bless. He didn’t doubt God’s willingness or power to do as he said he would do, but Abram just didn’t understand God’s confidence, since, heretofore, Abram wasn’t able to hold up his side of the bargain (covenant). I think we try to place our Christian understanding upon Abram some 1600 years before the giving of the Holy Spirit. We know how this turned out, but I don’t believe Abram had any concept of God performing a miracle in order to fulfill his promise to Abram. What Abram was doing was trying to fit God’s promises, which he believed, into his understanding of how things were done, and it simply didn’t make sense. In this context we should read Abram’s question: yes, but, “whereby shall I know that I’ll inherit?”
Abram asked God to teach or explain to him how his promise could take place, because Abram simply had no idea. His question had as much to do with himself as anything else. What am I doing wrong? How am I preventing your promises from taking place? Help me to understand what I’m supposed to do. It is this sort of thing that, I believe, was going on in Abram’s mind, and it is this that he took to God, and what follows verse-8 is God’s reply.
God told Abram to prepare the traditional sacrifices that concerned a covenant between two parties, and Abram did as he was told (Genesis 15:9-11). As the sun was setting God’s reply came to Abram. God caused a deep sleep to come over Abram, and God told him in a dream what would occur. He explained that the present tenants of the land were not evil enough to judge, so it would be awhile before Abram’s descendents could take possession. God also told Abram that his descendents would spend 400 years in another land until they were ready to take possession of their inheritance. Moreover, they would be ill treated as guests in that nation, but God would judge that nation as well, and Abram’s descendents would come out of it with great possessions.
All of this is an explanation to Abram of what would occur. God was showing Abram that God knows what the future is. If Abram didn’t know that before this, he knows it now, and believes God. In other words, God gave Abram a vision of what would take place. He didn’t explain how all this would occur, but God told Abram that it would occur, and this seems to have satisfied Abram. Nevertheless, God explained to Abram some of the details that he could expect that concern his descendents. Then as Abram awoke he found God as a smoking furnace and a burning lamp was going through the animal sacrifices alone!
It was customary for two parties who made a covenant together to pass through the animal carcasses set up on both sides of a pathway. The idea was that, if either party should break the covenant, the offending party should be as those animal carcasses. Yet, when Abram awoke he found God going down that pathway between the animal carcasses alone. In other words, everything that Abram learned about his descendents was God’s responsibility to bring about. Abram’s part was not in producing an offspring but in believing God that Abram would have a son who would inherit, and God would be responsible to bring that about. This was a concept that Abram had to learn. He had to be told God had this power. The idea that God could do such a thing was completely foreign to Abram up to this point, and Abram still didn’t have a firm hold on its understanding, as we shall find out in chapter 17.