When do living beings appear?

In the 28th verse of chapter 2 of Bhagavad Gita for happiness, Lord Krishna tells Arjuna that the soul is not visible — they are only visible in the bodily form. And since this is the case, there is no need to grieve the soul which doesn’t die. There are two categories of people — those who believe in the soul, and those don’t. Lalwani explains further on the same in this episode.