God's Curse on the Children of the Third and Fourth Generation

The bible does describe god as placing curses on various people things. But we need to be careful here, because the israelites had a different world view and it changed over time as god worked with them. Early in their history, when god took them as his people, they weren't that different from other ancient near eastern groups. That's one reason that god had such a difficult time weaning them off polytheism and idolatry. It's also why jesus said that moses wrote them certain commandments, because their hearts were hard and they weren't yet prepared fully accept god's will.