changed your desire. And you can thereby purify yourself. There will be sufficient activities to execute the desire. But all those activities will be purified.
So, we don't have to stop our activities, nor our desires. But we have to dovetail them with the desires of the Lord, as Arjuna did. After dovetailing his desires with Sri Krsna's, his activities became more responsible. Just like a coward, he was refusing to fight. He was a  ksatriya , a military man. His duty was to fight for a good cause. And what is a good cause? Sri Krsna instructed him to fight: "It is My plan." What can be a better cause than this? When the Supreme Personality of Godhead says that this is My wish, what can be more important? And what can be a better purpose than one which is coming directly from the Supreme Personality of Godhead?
When we dovetail with the desire of the Supreme Lord, then our responsibility becomes more imperative, and we become more active than we are otherwise. In material activity you will get tired. This is the difference between material activity and spiritual activity. When you are engaged in spiritual activities, you'll not get tired. You will have newer and newer strength to act. Therefore, desire is not to be stopped; activities are not to be stopped. Whatever potency you have in you, that is the potency given by the Supreme Lord, because you are the part and parcel of the Supreme Lord. And if you utilize it for the purposes of the Supreme Lord, then you become dovetailed with Him, and your life becomes successful. You'll not be disturbed by material desires, you'll attain peace. The peace for which you are hankering in life after life, moment after moment—that you'll get at that time when your desires are purified and dovetailed with the Lord's. One who desires sense gratification, the enjoyment of material satisfaction, will never be happy. That is not possible. If you want peace, if you want happiness, if you want perfection in your life, then just begin to dovetail your desires, activities, and potential with the Supreme Personality of Godhead. Then you will see what real happiness is, and will be able to tell who is really crazy.