Eternal life has been sought after by adventurers and seekers down through the ages. In the core of our being there is a chord that resonates with the power of this force of life. We have an inborn desire to protect that life and to struggle against things and circumstances that would harm that life. Life is a spiritual force. It was given by God in the creation and will pulse beyond the end of time.
Physical life is the visible manifestation of life.
The physical ages, is damaged or otherwise falters and fails. But the power, the force that is that person continues. They are simply released from the shackles of this physical body and world. Eternal life, according to Jesus, is to know God. In knowing God personally, His salvation is given to you.