One should know, realize or believe that the results of the good or bad actions done by him in this birth have to be experienced by him alone i.e. his "Atma" alone either in the next birth or in the other world. "Atma" means self only - say Charvakas that "Sareeram" or body is only "Atma" but not different from it. If that is so, then this "Atma" or self also should get destroyed along with the body. Then it has to be accepted, that the result of all his actions good or bad will also be destroyed along with the body. In that case he has to agree that there is no "Punyam" or "Papam" i.e. good or bad which is ridiculous. Therefore to say or believe that there is neither "Punya" nor "Papa" cannot be called as Hindu Religion or "Astika Matam". Therefore the first foundation stone for "Astika Matam" or Siddhanta is "Atma Nirnayam". That his self or "Atma" is different from his body - is the first characteristic for "Astika Matam".
The second characteristic is, to believe that his self has to take on another birth after rejecting the present body. This is called "Janmantara Visvasam".
The Third characteristic is, to believe that "Karma" or action is the root cause for taking another birth. The Hindu religion in its wisdom prescribes and tells at length the good deeds or actions to be performed by the self during one's life. This is stated in fourteen books popularly called as "Chaturdasa Vidyasthanams". These are the four Vedas - Rig veda, Yajurveda, Atharvana Veda, Sama Veda and Six Vedangas - Siksha, Vyakaranam, Kalpam, Niruktam, Jyotisham, and Chandas and four Upangas - Mimamsa, Nyaya Sastra, the Puranas and Dharmasastras - total fourteen, Chaturdasa Vidyasthanams.
The Fourth characteristic is, to believe that there is God to confer the result of one's actions done in this birth.
The fifth characteristic is to pray or serve God in the shape of "Vigraham" or idol form, called idol worship. All most all religions of the world are following the idol worship in one form or the other.
The Sixth characteristic is, to believe firmly that there is another world or "Paralokam" to experience the result of all actions good or bad done in this world and in this birth.
The Seventh characteristic is, to believe in the existence of "Punya" and "Papa" or the results for doing good deeds or actions and bad deeds or committing sins.
The Eighth characteristic is, to follow scrupulously the duties ordained by the Vedas to each of the people born in the four varnas namely Brahmana, Kshtriya, Vaisya and Sudra in their four Asramams, i.e. Brahmacharya, Grihasta, Vanaprasta and Sanyas Asramams, applicable to all of them.
The Ninth and the most important characteristic is, to believe in the sayings of the Vedas prescribing dos and dont's for the good of the people, protecting them from committing sins.