There are two main traits which prevent a person from serving the Almighty: anger and giving in to desires.
In the case of anger, the goal needs to be to totally conquer it.
But with desires, it is necessary to eat to have the energy to serve the Almighty and for the upkeep of one’s body. Therefore, while it is necessary to break one’s desires, you always need to keep part of those desires.
This is more difficult to master than a trait that must be overcome completely. ~ Vilna Gaon