How can the sins of our ancestors have any effect on us today, considering we have been saved and covered in the redemptive blood of our Lord Jesus Christ?

This seemed a strange concept to me. And yet working as a nurse I see generational sickness, and have been told countless times by patients “My mother had the same problem and her mother too” and children of a family all suffering from the same health problem as they get older. We see and hear stories of alcoholism running in families, children of abusive parents growing up to do the same to their children etc. There definitely seems to be a weakness that follows through families, it is simply because they are more susceptible to the same sin as their parents?.

In this verse we can see that we can experience the consequences of our Fathers sins, this goes back to Adams sin where we are all born into the dominion of death and disobedience to God. This means we automatically inherit the sin nature at birth. "All have sinned and fallen short of the Glory of God". We sin because it is in our nature to sin and we inherit the original sin of Adam and we inherit the generational blessings or curses of our physical father passing down the consequences of his nature to us.

We know if a child was conceived a bastard that it is a sin against that child our other children and that curse will bring its problems through the generations.

The good news is:-

In the Old Testament when a man is hung on a tree, it represents the curse of God, We are all cursed in our sins and the punishment for that is death and to be hung on a tree. But Jesus came to redeem us from the curse of the law by becoming a curse for us, by hanging on a tree on our behalf. He took our sins (and curses) on His body, Deuteronomy 21:22-23

But there is more good news in the bible and the blood of Christ Jesus that what we bind on earth is bound in heaven and what we loose on earth is loosed in heaven.
So what we need to do is:-

First, we confess our sin and our ancestor’s sin towards God.

Second, we forgive them for what they have done to us.

Third, we break any curses brought on us by ourselves and our ancestors.

Fourth, we can cast out the demons that came in through curses and sin

The consequences of the sinful nature can be stopped by faith in our Lord Jesus Christ