In Exodus 20:5-6, God talks not only iniquity (or sin) enduring out to the third and fourth generation – but also righteousness. This implication is one consistent with the character of God modeled in the rest of Scripture – love. It is the principle of actions leading to consequences. So God essentially says here that people have a choice to follow in a path of sin, or a path of intimate relationship. This is echoed later on in a passage in Deuteronomy 11:26. God here says, “See, today I am setting before you today a setting and a curse!” (NASB).
I didn’t have much reason to disagree with this on a free-will basis. But I have recently encountered the field of Epigenetics. In this field, It is theorized that the behaviors, and activity patterns performed by the parent leaves marks on the genetic code, that (as I understand it) makes it easier for the child to follow the habits and patterns their parents had. It doesn’t mean that the child is locked into a wicked lifestyle, as if they have no choice in the matter – but it would suggest that they are influenced by their genetic sources.
I am of the opinion that God was very particular when it came to fabricating the human genome. Some have called it “the signature of God”, and it would follow that seeing how the original intent of man was intimate relationship with God, several subsequent relationships after would hold the moral and physical patterns of their righteous forbearers. Of course, after four generations, there is a release, and that is just a limit that should be developed by God in His plan, as it releases man to be the best control of himself, while still have a subtle influence towards what is right.
But what does this mean for several millennia later? Even though after the fourth generation the individual is no longer affected by his great grandfather, his grandfather’s slight various now make up the difference after his off-spring. So there has been a subtle shifting of righteousness from the first man to mankind today, and genetics now brings out the empirical proof.
It is fascinating to see the discoveries of science align with Scripture, knowing that the passage is in question is understood in the context of its place in Scripture. But it is also a tragedy to discover that our subtle little compromises have slowly led us away from God… Slowly led us away from our design… Slowly passed on patterns that have dwindled our lifespans to a fraction of what they were meant for (if there was originally a cap on our life) (See Gen. 2:17; 3:22). So sin has only brought death, but we were brought from forever, to 969 years, to 300-some years after the flood, to about 80 years of age.
God is the great geneticist! He knew that we pass on our chromosomes to our offspring, and He knew there was more than just instructions for unformed stem-cells. He knew to put inhibitors in certain places to prevent some unintentional evil to develop. He understood that if the parents are drinking alcohol that it would affect the fragile child in the womb. He understood stress transfers through the nervous system; and the tightly-woven systems inside the incredibly-elaborate human affect any new creatures that might be developing inside of it.
Now our discovery of human physiology, anatomy, genetics, nutritional and fitness habits have given us a greatly maximized lifespan, but nothing like what was originally meant for us, and restoring that will mean several millennia of following God. It would be very surprising if were able to look at Scripture as a foundation for scientific discoveries, and restore some unprecedented new gains in lifespan, or fulfillment, or development of new methods to visit The Creator’s cosmos?