“Imagine there’s no heaven” John Lennon sang in 1971. Heaven and Hell, his song argues, keep us from dealing with the here and now, from living together in peace and harmony. Not that atheist systems have a great track record for making the world a better place!
Heaven for Christians is first and foremost something that has taken place in history. Jesus on the cross entered into the mystery of human death, only to conquer. In rising from the dead he ushers in a new age of human life, living in a transformed way before the Father.
For Christians, this life with Jesus is something that affects us here and now, that makes us value and love the world around us in a completely new way.
The road to eternal life is through loving here and now, even to the point of dying on the cross. Jesus did this, and invites us to take up our crosses, and to follow his path of generous love.