There is only One World, but there is a big dividing line between those who are comfortable, happy, healthy, and safe, and those who are in pain, miserable, sick, and in danger. We cross the lines involuntarily at times- but we can also choose to cross over for periods of time from the happy place to the places of sorrow. This is being poor in spirit, this is compassion, this is prayer, this is where we love our neighbor as ourselves, where we love our enemies, where we develop our Christ-likeness. We cross over not because we have to, but because we choose to love.