And every time he pushes it away, the bad falls down, and through this, G-ds light gets revealed in the world even more than before. And therefore one should not be sad, even if he is spending his whole life on this 'war', because maybe this is why he was created, to always overcome the bad. And this is what Job meant when he said that G-d created sinners, he did not mean that G-d created people to be sinners, since every person can control himself, rather he meant that there are some people which were created in order to have bad thought just like the sinners, and they will not be able to get rid of them, because that is done only by a tsaddik.