A wealthy and learned Chasid came to the Bal Hatanya complaining that his business was going bad and he was losing all of his money fast. He told the Rebbe that if Hashem wills him to be poor, he accepts it with love, but he can't bear the pain of all the people he owes money to. Many poor people, orphans and widows had entrusted him with their money, and he can't even pay them back! The Rebbe was leaning on his arms listening, and finally said "you seem to be worried about what you need, but you haven't perhaps considered what you are needed for?" The Chassid fell into a dead faint. When they revived him, he left the Rebbe's office and went straight to the Beis Medrash where he sat for days on end, completely ignoring this world and any past worries of his... Finally the Rebbe called him and told him that Hashem wants us to serve him through this world, not by ignoring this world, and the Rebbe blessed him and sent him home. From that point on, he saw much success and recovered all his fortune...
What I found beautiful about this story is that although it is true that this Yid had very valid reasons to be worried and feel tremendous pain - and we would even go as far as to assume that it was his "Yetzer Tov" who was making him worry (after all, he was feeling the pain of others, to whom he owed money) - still, the Rebbe's reply to him was not to focus on what HE NEEDED, even for the good (i.e. yetzer hara, struggle, reward, nachas ruach, etc...) and instead focus on what he is needed for, i.e. being useful to HASHEM. And when a Jew succeeds to make this paradigm shift in his thinking, he ends up seeing success anyway
It's a subtle but MAJOR distinction. This is that "nekudah" that is spoken about in Chassidic Sefarim... the difference between Chametz and Matza, between Lishma and Shelo lishma. (But as Dov will surely tell you, the only things that matters to him is that it's the ultimate difference between sobriety and insanity, life and death ).