The lawyer writes this letter on the night before he is due to win the bet and win back his freedom. According to the lawyer, before he is free to enjoy his life again, there are a couple of points that he wants to make clear to the banker.
First of all, the lawyer says that he despises "freedom and life and health." Anything that can be considered as one of life's pleasures is no longer desirable or enjoyable for the lawyer.
Secondly, in his letter, the lawyer also says that he has spent the last 15 years immersed in the world of his books. Thanks to these books, he has been able to experience a wealth of different scenarios, including watching the sunrise, climbing mountains, performing miracles and having relationships with women.
Next, he says that, although these books have given him lots of wisdom, he feels that this wisdom is pointless because he now knows the truth about every aspect of human life: that it is "worthless, fleeting, illusory, and deceptive." Everything that man craves and enjoys is actually pointless and the lawyer despises all of it.
Crucially, based on this view, the lawyer renounces the two million rubles that he once described as "paradise." Money is no longer of any interest to the lawyer because he now despises human materialism.
In order to forfeit the money, the lawyer intends to leave his cell five hours before the deadline, therefore ensuring that he loses the bet.