The concept of the "generational curse" is a simple one that has been repurposed by the deliverance ministry. Generational curses are mentioned only in the Old Testament:
What does the Bible say about generational curses?
You shall not bow down to them or serve them, for I the LORD your God am a jealous God, visiting the iniquity of the fathers on the children to the third and the fourth generation of those who hate me, but showing steadfast love to thousands of those who love me and keep my commandments. (Exodus 20:5-6; cf Numbers 14:18; Deuteronomy 5:9)
The generational curse mentioned in the Bible, then, was a warning given to Jews that they were to worship only God, not idols. If one generation fell away from God and worshiped pagan gods, God warned that He would "visit the iniquity" on several future generations. How is this fair? God dealt with the Israelites differently than He does with members of the church. Everything an Israelite did affected the entire nation (see Joshua 7). Since the Messiah of the world was to come out of Israel, all of Israel needed to follow God.
But God did not leave the Israelites with no hope (Leviticus 26:39-42). Numbers 14:19-20 show that forgiveness was available to all Israelites. And Exodus 20:6 explains that God's lovingkindness to those who repented and followed God would be granted for thousands of generations. This clearly infers that the generations being punished for their fathers' sins did not repent and seek forgiveness, but continued their fathers' evil ways.
The threat of the generational curse is over, however. Jeremiah 31:29-31 and Ezekiel 18:1-4, 14-20 all say that under the New Covenant the son will not be punished for his father's sin. We are freed from the generational curse. Jesus' sacrifice heralded the coming of the New Covenant (Luke 22:20), and we enjoy the benefits.
So how is the concept of "generational curses" used today if the Bible so thoroughly explains it is no longer valid? Some deliverance advocates seem to just ignore the evidence. Others believe that a generational curse is only handed down to non-Christian family members; once a person accepts Christ, he is free. But a sin or hardship can be passed down from generation to generation via a demon that stays with the family. Such a family may have a history of cancer or unfortunate luck with finances. They teach that a child can be inhabited by the family demon, which can remain dormant until awakened by sin. Accepting Christ for salvation breaks the generational curse, because we are under the new covenant, but it does not remove the demon, which can still wreak havoc. The cure is to repent of any sin affiliated with the curse and remove the demon.
There are two issues with this. The first is that Scripture indicates Christians cannot be demon possessed. The second is that generational curses were never said to involve demonic forces. Exodus 20:5-6 and the other verses clearly state that God punished the generations. There is no mention of a "bondage" or illness or even the curse of a sin passed down by the work of a demon.
Are there generational curses today? Not in the sense mentioned in the Old Testament. It is true that whether by influence or genetic predisposition, families can see sins like addiction or rage pass through several generations. "Bondage" issues such as ill health or misfortune can be explained the same way. A demon is not necessary to pass heart disease to the children of parents who don't know how to eat healthfully.
"Deliverance" from such a situation is straightforward for the most part. We take our sin to Christ, ask Him to heal us, and work with Him by refusing to continue sinning. For health issues, we can ask for healing, but it doesn't mean God will see fit to cure us. But if one generation rejects God or becomes a Freemason, it doesn't mean a demon will give the next four generations diabetes.
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