Life is not something granted to some forms and not to others. Gravity doesn't affect some things and ignore others. All forms have to deal with the force of gravity and the same is true of life. Simply because the rock or the sand do not seem to move about, or eat, does not mean they are not alive. The fact that life doesn't animate all beings equally doesn't make them less alive than we are. 
    When it come to eternal life though, we are talking about something else. Only spirit is eternal so only the spirit of a man, a dog, a flower or a stone is eternal. The material may seem eternal because when a material being is destroyed, the atoms and molecules that it was made from do not disappear, they are used to form new things, new life forms. And eventually—we believe soon—the material universe will end and everything will be turned back into it's original spirit form. So in that sense, even the material world is eternal, but here is the difference. 
    During our lives as material beings, we humans have the ability, with the help of God, to awaken our souls and become a completely unified being. Then, when our physical body dies, our spirit and soul and that which is out true self will survive intact and move into the World of Light as a complete individual. 
    The frog, the tree, the rock cannot do that. When they are destroyed, the spirit that held them together simply forms a new life form and continues to do that over and over again. So what once was a frog may now be a rose bush. SO the physical frog is gone and the spirit is not a frog spirit now so the life form we call “frog” is not eternal. The spirit is, but the spirit was only temporarily a frog spirit. It may also have been a cow spirit, a tulip spirit, and a rock spirit. That is the difference.