We may get the question: “Why do we need to give up material desires like lust and greed?”

Because of their two deadly characteristics: insatiability and irresistibility. To understand these characteristics, let’s compare engaging with material desires to playing a game. 

Insatiability: When we say yes to material desires, they become not pacified, but aggravated. They force us to repeatedly, even perpetually, keep saying yes to them. Analogically, trying to fulfill the material desires is like trying to win the game. But, as these desires are insatiable, they just don't allow us to win.

Irresistibility: When we get fed up with the futile attempt to fulfill these desires and decide to say no to them, they charge into our consciousness regularly and relentlessly, and seem impossible to resist.  Analogically, wanting to give up material desires is like wanting to quit the game. But as these desires are irresistible, they don't allow us to quit.

Thankfully, we have a third alternative: switch to playing a different game altogether. 

All of us have an innate undeniable need for happiness. That’s what makes us indulge in material desires. When we try to give up material desires, we try to deny our need for happiness. As this need is undeniable, material desires feel irresistible – but only as long as we don’t know any happiness other than the material. The Bhagavad-gita (02.59) indicates that material desires become tolerable when we experience a higher, spiritual happiness. In practicing devotional service and relishing spiritual happiness therein, we metaphorically switch to a different game – and thereby free ourselves from the doomed game with material desires.

Bhagavad Gita Chapter 02 Text 59

“Though the embodied soul may be restricted from sense enjoyment, the taste for sense objects remains. But, ceasing such engagements by experiencing a higher taste, he is fixed in consciousness.”