How can I reply to a devotee's argument on Brahma's life?

[Shri Durgaprasad asked: Paadanamaskaaram Swami, I was discussing with a devotee of Krishna, who says only Vishnu is permanent. He quotes a verse 'avyaktad vyaktayah sarvah (8.18)... from Gita (authored by A. C. Bhaktivedanta Swami Prabhupada), the purport of which talks about life of Brahma, though the verse literal translation doesn't speak about life of Brahma. The purport for 8.18 goes like this: "The jivas (individual souls) remain compact in the body of Visnu and again and again are manifest at the arrival of Brahma's day. When Brahma's life is finally finished, they are all annihilated and remain unmanifest for millions and millions of years...".

What is the real meaning of this verse? How can I reply to his argument on Brahma's life?

Kindly enlighten me. At Your lotus feet, -Durgaprasad]

Swami replied:- Here, Brahma means the assistant of God Brahma assisting Him in the creation and he is called as Prajaapati (Svasutāyāmakarot Prajāpatiḥ). It is this Prajaapati, who stole cows and cowherds of God Krishna due to ignorance. God Brahma, God Vishnu and God Shiva are the incarnations of God Datta and God Krishna is also the incarnation of God Datta. Hence, God Brahma and God Krishna are one and the same God Datta. Prajaapati is also called as Brahma in an approximate sense. A Deputy Collector sitting as in-charge in the chair of the collector is called Collector only. Hence, the life of Brahma spoken here means the life of Prajaapati. The meaning of this verse is that the creation manifests from subtle state to gross state after the dissolution of it, there by meaning that the creation does not become non-existent after dissolution.