Every piece of information that we need regarding what was occurring in Judah is not supplied in Jeremiah 5, but the basic lie was religious. It was Baalism, to use a general term. It began when the priesthood deceived itself into allowing a bit of falseness to creep into their preaching, and they convinced themselves that a little bit would not hurt at all. It would be all right. What they did over time was to gradually severe their mooring to God's law and the restraints contained in it.
The implication in verses 30-31 is that even those who say that they are looking for truth really are not. When a society gets this corrupt, they have no idea what truth is anymore, and God says they had come to the point that people loved to be lied to.
A few years ago the whole nation watched the Senate hearings concerning Oliver North and Iran Contra. It was interesting, in terms of this sermon, because Oliver North admitted that, in the national interest, he lied to a Congressional committee. That was his justification: It was in the national interest to lie. Oliver North came out of those hearings a hero. The people loved it because of his persona. He "looks" so nice, so clean. He was so dynamic and sharp. Yet, he was a liar! And the people loved it.
This is actually not unusual because we have reached the state in American culture where lying is taken for granted in the political arena, in the relationships that we have with other nations. It is part of the game. Everybody knows that everyone else is lying in their national interest. Nobody trusts anyone else.
President Eisenhower lied to the whole nation when Gary Powers was shot down in a spy plane over Russia (the U2 incident). So, in a report to America, he lied. Did President Nixon lie to us? Of course he did. And who knows how many other lies are said for the sake of politicians' careers!
John W. Ritenbaugh
Truth (Part 1)