How do you respond to Genesis 15:13–15?

The Lord tells Abraham that his offspring “shall be aliens in a land that is not theirs, and shall be slaves here, and they shall be oppressed for four hundred years; but I will bring judgment on the nation that they serve, and afterward they shall come out with great possessions.”

This passage may constitute a conditional prophecy which could have been modified had circumstances called for it. Many if not most prophecies in the Bible are conditional (cf. Jer. 18:7–10). They are not mere previews of an unalterable future. They rather reveal God’s present intentions, assuming things don’t change.

On the other hand, the passage may indeed constitute an unconditional prophecy. In this case the passage reveals a now-unalterable feature of God’s providential plan. The sovereign Lord of history who is ultimately in control of the movement of the nations (Acts 17:24–28) deemed it wise to ensure that his future people would be in captivity for four centuries. It is important to note, however, that the Lord would not need to control and/or foreknow every other detail about human history to accomplish this. The Lord of history who grants whatever degree of freedom he wishes to grant to his human subjects can control and foreknow aspects of the future and guide history toward his desired goal without micro-controlling and foreknowing every detail along the way.

Some have trouble conceiving of how God could settle some things about the future without settling all things about the future. But if we reflect on the matter a bit we will see that we ourselves live with the assumption that some things about the future are settled and some things not. We assume control over certain aspects of our future without feeling the need or desire to control all aspects of our future.

For example, a person may resolve that she is going to be a teacher. This much has become certain to her, but surrounding this now-unalterable destiny there is a myriad of contingencies that remain uncertain. Exactly what kind of teacher will she become? Exactly how long will it take to complete the training? Exactly where will she eventually work? These and a million other questions about her future may be left open without calling into question the certainty that she will be a teacher.

The fact of the matter is that every particular thing we determine about the distant or immediate future is a determination made within the context of many indeterminate variables. Why is it, then, that many feel the need to assume that if God predetermines and/or foreknows some things about the future he must predetermine and/or foreknow all things about the future? This all-or-nothing conclusion is not consistent with the biblical account or our experiences.