Ah. I should have been more careful with my wording. Not "found nothing", but found nothing except the body, the various sensations and what we make of them, and the ongoing stream of consciousness. No spirit, soul, homunculus or anything that can zip out of the body at death and enter another body.
And yet, this life is not impotent. What we do here has countless effects into the future, so we need to behave ethically if peace is to be achieved. What then, carries on if it's not one's consciousness or spirit?