Viṣṇu does not require anything in order to create. He does not require the goddess Lakṣmī in order to give birth to Brahmā, for Brahmā is born from a lotus flower that grows from the navel of Viṣṇu. The goddess Lakṣmī sits at the feet of Viṣṇu and serves Him. In this material world sex is required to produce children, but in the spiritual world a man can produce as many children as he likes without having to take help from his wife. So there is no sex there. Because we have no experience with spiritual energy, we think that Brahmā’s birth from the navel of Viṣṇu is simply a fictional story. We are not aware that spiritual energy is so powerful that it can do anything and everything. Material energy is dependent on certain laws, but spiritual energy is fully independent.