Eternity is something hard for us to fathom other than to say that it is without end. We humans live in time but God inhabits eternity. (Isaiah 57:15) Or as the Psalmist said, “Even from everlasting to everlasting, thou art God.” (Psalm 90:2)
The good news of Christianity is that eternity can be ours also. It is pretty certain that man was created for eternity but then sin entered and death became the lot of every man. But still there exists within the human breast a longing to live on and on. And now life and immortality have been brought to light by the gospel. (2 Timothy 1:10)
Yes, we die and along the way we groan within ourselves as we feel our bodies weaken with age until finally we are planted in the earth but for Christians it is only to wait for “the redemption of our body.” (Romans 8:23) At which time not only will life be restored but it will be with an eternal, immortal vigor as we enter the portals of heaven.