After the exile, when they came back in the land, starting in the year 539, there were some major concerns that occurred during that time that different prophets and different leaders had to address. When they first came back in the land under Zerubbabel and Joshua the high priest, one of the first concerns was the reestablishment of the temple, the building of the second temple. And as they were doing that, they had a good start, but then they started slowing down because they got concerned about building their own houses. They started worrying about their own well-being as opposed to the worship of God. And so, the prophet Haggai came along and rebuked the people and said, hey, wait a minute; let's not get so concerned in our own ways, in our own things that we neglect the worship of God. And so, if we want the blessing of God, we need to make sure that this temple gets built, that we reestablish the sacrifices, and so forth. Of course, there were other concerns at that time as well about who is exactly a priest. And so, again, they had to do different things to determine who was a real priest, who was not part of the priesthood, and so forth. But as time went on, when you got to the time of Ezra, Nehemiah and, sort of, those latter prophets, again, like a Malachi, you can see that they had the same problems as they did in other generations and that we see today of wanting to go away from the Lord, go into things like idolatry. As a matter of fact, they started intermarrying, which the Bible really warned about that, that they should not intermarry with the surrounding nations because that's what led to idolatry. And so, that's why Ezra did something that was quite unique, and that is, he did forced divorces, but that saved Israel from going through another round of idolatry. And as you read Malachi, you see there was all sorts of things that, again, the priests were starting to go into an apostate sort of state, condition, and so he was calling the Levitical priests back to their duties. He was calling people back to tithing and doing what the law of God teaches. So, again, what you see in almost every generation is a tendency to move away from God and his word, from his law, and so what you saw there was, again, the prophets and the last fellows, the last leaders like Ezra and Nehemiah, calling people back to their covenant obligations.