(But if I get my spiritual body, immediately, within a second, I can reach kingdom of God, the spiritual world. Spiritual body is so powerful and so, I mean to say, swift, because it is swifter than the mind) 



You get this from Bhagavad-gītā. Mind is swifter than anything, than the air even, than the ether. You are sitting here, and immediately you remember twenty thousands miles away your home—immediately you go. This is the swiftness on mind. But the soul is still swifter than the mind. So as soon as you, just like in this fourth chapter you have read, Kṛṣṇa says:
tyaktvā dehaṁ punar janma
naiti mām eti kaunteya
(BG 4.9)
"Just after giving up this body, immediately he comes to Me." It is so swift. So we have to seek after that swiftness of my spiritual body. Immediately I transfer."
(Prabhupada Lecture, January 22, 1969, Los Angeles)
Comments
"... We are thinking we are apart from Kṛṣṇa, separate from Kṛṣṇa, or we do not know Kṛṣṇa, although we are in touch. So that is to be cleansed. The via media impediment has to be cleansed." -HDG Srila Prabhupada