Karma, souls, rebirths, all of them is very intricately
connected. To believe in them is a matter of faith. As per our hindu dharma and
also Bhagvat Gita, this body is not the real me. The soul within is what is the
real me. And this soul never dies. As Lord Krishna tells us in Gita:
Vaasaansi jeernaani yathaa vihaaya navaani grih-naati naro-aparaani
Tathaa shariraani vihaaya jeernaanyanyaani sa-nyaati navaani
dehi.
"During our daily lives we change our old and/or dirty
clothes and put on new and/or clean clothes whenever the need arises.
Similarly, the soul or aatman casts off its worn out physical body and takes
residence in a newer physical body at regular intervals in time."