Vedas reveal that the soul continues to exist forever. From the different studies, we know that there was life on earth before our birth and society continues after someone dies. So we know that the soul must continue to remain in existence. Where it goes nobody knows except the higher authorities – Saints, but the guarantee is that somewhere rebirth will take place in some type of body. The soul enters the next kind of body as per the desire and attachments created in the past lives. Matter is considered the playing field where the jiva, or individual living entity, gets to act out its desires.
Lord Shree Krishna says to Arjun “Besides this inferior nature, O mighty-armed Arjun ! There is a superior energy of Mine, which are all living entities who are struggling with material nature and are sustaining the universe.” (Bhagavad-Gita 7.5)