The Bhagavad-Gita provides information regarding:
- God (Isvara)
- Souls (Jivas), the living entities like you and me
- Time (Kala)
- Activities (Karma)
- Material Nature (Prakrti)
No other scripture on the planet provides this information. From the above five, karma is temporary and the others are all eternal. Thus God, living entities, time, and matter are eternal.