A wicked man once went to a Guru (preceptor) for initiation into spiritual life. The Guru asked him to give up at least one of his bad habits; he gave up uttering falsehood.
That night, when he went to the Royal palace to commit theft, he found on the terrace another person, who said, he too was a thief. He too announced that he was a thief and both broke into the treasury and divided among themselves the diamonds found there. The other person was none other than the king; he pretended to be a thief and he knew where the keys of the treasury were. While the diamonds were shared, the honest thief felt pity for the King of the realm who was losing his entire stock; he asked his companion to leave one diamond behind, in the safe. And, it was done.
Next morning, when it was discovered that the treasury was looted, the Minister was sent by the King (who had acted as thief the previous night) to assess the loss. The Minister found the diamond, thinking that had missed the eyes of the thieves. He quietly transferred it to his own pocket and reported at court that all the diamonds were gone!
The King had got from the honest thief his address, the previous night, while they parted company, with their separate bags. So he sent for him and when stood in court before the King, he confessed that all but one of the diamonds were stolen by him and his unknown associate. The diamond was discovered in the pocket of the Minister and the King dismissed him for the lie. The honest thief was appointed Minister, instead, and he gave up his other evil habits too and pleased his Guru, by his fame as a virtuous administrator.
It is a perfect example of how one step in the right direction can led to another.
