Not a very precise theological term but is often found in popular teachings about how God deals with us in regards to the sins of our fathers and forefathers. The term can be understood in two entirely different senses; unfortunately it is almost always not defined when used and this has contributed to not a little confusion.
1). The term may simply refer to the effects of the sins committed by a past generation on subsequent generations. This is biblical. Adam's and Eve's rebellion left all of humans constrained in sin. The refusal of the generation of Israelites who left Egypt for the Promised Land to enter and conquer the land from Kadesh Barnea because they feared the gianst that were reported by the scouts to inhabit the land delayed their descendents's inheritance of the land for 37 long years. What we decided to do in our relationship with Christ today will shape the spirituality of our children tomorrow. Understood in this sense, the idea of generational sin is biblical.
2. A popular teaching, peddled around quite a bit in the 1980's among tele-evangelists and those involved in the deliverance and spiritual healing ministries, understands the term different. It claims, mainly on the basis of Exo 20:4-6, that God will punish us—even if we have accepted Christ—for the sins of our fathers "to the third and fourth generation." This teaching represents a distorted reading of the text and is totally unbiblical. Scriptures is quite adamant that each individual—while they may, as noted in 1) above, suffer from the effects of his/her forebear's sin—is free from God's judgment for sins other than their own. A full article refuting this teaching is available in ALBERITH:
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