To gain eternal life is to be permitted to live forever as a conscious human spirit. That is the ultimate goal of all human beings. After having passed through all the realms of material Creation and have come to know it and after having perfected all our abilities, we return to Paradise which we left as unconscious human spirit seeds at the beginning of our wanderings as perfect, self-conscious human spirits. We will then be given the gift of eternal life. The ability to remain as a self-conscious contributor to the further development of Creation for ever.
The core of the human being which is spirit is itself eternal but eternal life denotes conscious activity. It denotes the development of the spiritual personality which was lacking when it left the Spiritual realm as a spirit germ. His personality becomes perfected through his experiences and as a result he is allowed to become a permanent member of this Creation with duties and responsibilities.