Actually, there is nothing as materialism. Materialism means forgetfulness of God, that's all. Just like in the Bhagavad-gītā it is said, bhūmir āpo 'nalo vāyuḥ khaṁ mano buddhir eva ca, aparā . . . prakṛtir me bhinnā aṣṭadhā (BG 7.4). Materialism means that you are dealing with earth, water, fire, air, or the ether, or mind, intelligence, so far. These are the subject matters of studying materialism. But God says: "They are My separated energies." These matters . . . you have not produced this earth, water, air, fire. That's a fact. That is produced by the energy of God. So while dealing with material things, if you remember that this material thing is produced by God, then you are perfect.
And if you theorize that it has dropped from the sky, then you are materialist. That is the difference between materialist and spiritualist. A spiritualist knows that wherefrom this earth has come, wherefrom the water has come, wherefrom this fire has come. Then he is spiritualist, God conscious. And one does not know, he's ignorant. Actually, that is the fact. But one who is ignorant of the fact, he's materialist. And one who knows the source of this material elements, he is spiritualist. That is the difference. Therefore the conclusion is one who does not know God, he is materialist, and one knows God, he is spiritualist.