The people, they do not know it. They are thinking that, "Whatever I am acquiring in this body, that will go with me," or "I shall be happy with these acquisitions." That is called illusion, māyā. Because they have no knowledge that "I am spirit soul. I am changing this position of different bodies." Vāsāṁsi jīrnāṇi yathā vihāya (BG 2.22).
Just like we change our body . . . our dresses. This knowledge is lacking in the present civilization. They want to make permanent settlement here but forget that "Any moment, I shall be kicked out of this situation. I shall have to accept another situation." That is the lack of education in the modern civilization. They are accepting something temporary as permanent settlement. This is called illusion.
So in this verse Kṛṣṇa advises Arjuna, "My dear Arjuna, these Kṛṣṇa consciousness activities, even if you achieve one percent result . . . what is that result? Bhakti. Bhaktiḥ pareśānubhavo viraktir anyatra syāt (SB 11.2.42). This Kṛṣṇa consciousness, or bhakti, devotional service, means to develop attachment for Kṛṣṇa, and in the same proportion develop detachment for material sense gratification. Two things cannot go on. Just like here is a glass containing water. If you want to put milk in this glass, then you have to throw away the water.