One of the main things that stop Hashem from giving Beracha, blessings to a person: shefa (abundance) is always being thrown upon us from Shamayim (heaven). As the Ramchal says, the sun can be beaming outside at midday, but if you decide to close the window shades, the sun is not coming in. Hashem is still beaming, the sun is still beaming, the light is still there, but you decided to close off the light from coming into your room by closing the window shades.
Hashem's Beracha—Hashem's shefa—is always beaming, Beracha, Beracha, but you can have humans who damage their own lives and speak Lashon Hara (evil speech), says the Chafetz Chaim. When you speak Lashon Hara, you're closing the pipes, you're closing the window shades; the shefa can't come into your life. Lashon Hara is extremely damaging, says the Chafetz Chaim. A person who speaks Lashon Hara, Hashem doesn't want to get involved in his life. He stinks. He doesn't even want to go near him. Those are the words of the Chafetz Chaim: “He smells too much of Averot (sins); I don't want to deal with such a guy.” HaKadosh Baruch Hu! Lashon Hara is extremely damaging.
A person who takes upon himself not to talk Lashon Hara and learns this book or any book from the Chafetz Chaim—the point is being real about it: to try to take upon yourself to stop speaking Lashon Hara.