4. The reason from reason and free will
Our souls can perform two acts that are spiritual, not just physical; therefore, our souls must be spiritual. And what is spiritual is not mortal. Therefore our souls are immortal.
5. The argument from God
If there is no life after death, there is no God, and you have to be an atheist. For if God exists, then immortality must exist also.
6. The argument from the intrinsic value of a peron
If death is the end, and there is no life after death, then people are treated like cars. You can replace your car, but you can’t replace your friend. If reality treats people like cars, then reality is immoral. And if reality is immoral, why take morality seriously? If the deepest moral values—the intrinsic value of persons—has no ground in reality; if this idea that persons are intrinsically valuable and ought to be loved as ends rather than used as means—if this idea is only our subjective feeling or desire, then there is no objectively real obligation to love people, to treat them as ends and as unique and irreplaceable.