How does the material body become spiritualized by bhakti?

From Keshava Nimai P:

SP explains in Raja Vidya book about the example of Iron Rod and Fire.

“As we begin to make spiritual advancement while in the material body, we begin to take on the qualities of a spiritual body. If we put iron into a fire, it becomes hot, and then it becomes red-hot, and finally it is no longer iron, but fire—whatever it touches bursts into flames. As we become advanced in Kåñëa consciousness, our material body will become spiritualized and will no longer be affected by material contamination.”

What it means  ” Our material body will  become spiritualized” ?

Answer Podcast: