In Exodus 34:6-7 God said, 'The LORD, the LORD God, merciful and gracious, longsuffering, and abounding in goodness and truth, keeping mercy for thousands, forgiving iniquity and transgression and sin, by no means clearing the guilty, visiting the iniquity of the fathers upon the children and the children's children to the third and the fourth generation.'
A man's actions can have tremendous influence on his children. If he acts well, it can be a positive influence. If he acts poorly, the influence can have tragic effects. For example, if a man drinks excessively and mistreats his wife, there is a good chance his son will do the same, and there is also a good chance his daughter will marry a man who does the same. In the verse above, God says that He is behind this, but we believe this is better understood as, God set up life to work this way. In other words, people tend to pass both their sins and their goodness along to their children, who in turn pass them along to their children.
A powerful example of this is recorded by Al Sanders in his book 'Crisis in Morality!' He writes:
'Max Jukes, the atheist, lived a godless life. He married an ungodly girl, and from the union there were 310 who died as paupers, 150 were criminals, 7 were murderers, 100 were drunkards, and more than half of the women were prostitutes. His 540 descendants cost the State one and a quarter million dollars.
'But, praise the Lord, it works both ways! There is a record of a great American man of God, Jonathan Edwards. He lived at the same time as Max Jukes, but he married a godly girl. An investigation was made of 1,394 known descendants of Jonathan Edwards of which 13 became college presidents, 65 college professors, 3 United States senators, 30 judges, 100 lawyers, 60 physicians, 75 army and navy officers, 100 preachers and missionaries, 60 authors of prominence, one a vice-president of the United States, 80 became public officials in other capacities, 295 college graduates, among whom were governors of states and ministers to foreign countries. His descendants did not cost the state a single penny. 'The memory of the just is blessed' (Prov. 10:7).'
Two things we must be aware of: 1) this spiritual principle does not always play out perfectly, and 2) everyone has the power to stop the cycle by repenting and going in a different direction. Sadly, not that many people do this.