If you think that this (body) takes birth and dies perpetually, even then, O Arjuna, you should not grieve like this.

We are born into the world of nature; our second birth is into the world of spirit.

Because, death is certain for the one who is born, and birth is certain for the one who dies. Therefore, you should not lament over the inevitable.

Death is as sure for that which is born, as birth is for that which is dead. Therefore grieve not for what is inevitable.

For certain is death for the born and certain is birth for the dead; Therefore over the inevitable thou should not grieve