Since Adam, millions have died. They are either in heaven or hell. How can these places manage so many people? And what exactly happens in heaven and hell?

Apart from heaven and hell, there is a third possibility known as purgatory. Those in purgatory will ultimately enter heaven after being purified.

When a person dies, the soul leaves the body. Soul is a spirit. It does not occupy physical space. Even at Jesus’s second coming when the bodies resurrect and reunite with the souls, these bodies will occupy no space. Our resurrected bodies will be like that of Jesus’s body after resurrection. It could permeate obstacles. So space is not a concern.

Heaven is a reality that God has prepared for God’s people. The bible points out “What no eye has seen, what no ear has heard, and what no human mind has conceived, the things God has prepared for those who love him (1 Cor 2:9). In heaven we will be united with God in a one flesh communion. We will share in God’s very life. We will know God as He knows us (1 Cor 13:12). Heaven is knowing and loving God without end. 

Heaven and hell are not physical spaces located above or below the earth. These are states. Heaven is the state of being completely united with God in perfect love and knowledge. Hell is the state of being completely removed from God, hopelessly, torturously eternally united to evil.