So called material world

Room conversation, Nairobi, 29 Oct, 1975.

Prabhupada: There is no material. When you forget Krsna, that is material. Just like madness. Madness is not our natural position, but when your brain is deranged, then it is madness. Madness has no separate existence, but when our brain is not in order, there is madness. Similarly, there is nothing material, because everything has come from Krsna. The original source is Krsna. Aham sarvasya prabhavo mattaḥ; sarvam pravartate [Bg. 10.8]. So the material world, the so-called material world, has come from Krsna. So if it has come from Krsna how it is material? The cause and effect is the same, maybe differently manifested.

S. B. 4.28.42. Purport :

For the perfect devotee, the energy and the energetic are nondifferent. Thus the so-called material world becomes spiritual (sarvaṁ khalv idaṁ brahma). Everything is intended for the service of the Supreme Lord, and the expert devotee can utilize any so-called material thing for the Lord’s service. One cannot serve the Lord without being situated on the spiritual platform; thus if a so-called material thing is dovetailed in the service of the Lord, it is no longer to be considered material.

Class on S. B. 1.8.40.

Material enjoyment means sense gratification. That's all. That is the material world. And spiritual world means there is no sense gratification, only activities for Krṣṇa's satisfaction. That is spiritual world. The so-called material world can be converted into spiritual world when this Krṣṇa consciousness is there, that everything should be used for Krṣṇa's pleasure. That is spiritual world. Otherwise, it is material world.