Just like a citizen is supposed to remain free, but sometimes is put into the jail because he has worked under different criminal energy. So therefore he is put into the jail. But when he becomes perfectly civil, so there is no jail for him—he is free to move. So we have preferred to act under material energy—therefore we are suffering, there are problems. And if we prefer to act under spiritual energy, then we'll be happy. This is the difference.
So what is difference between material energy and spiritual energy? Material energy means one works for his own sense gratification, and spiritual energy means one works for sense gratification of Kṛṣṇa. That's all. There must be some sense gratification, working. But when we work for our personal sense gratification, that is called māyā. He cannot be personally be satisfied without Kṛṣṇa.