Science, simply put, is the observation, identification, description, experimental investigation, and theoretical explanation of phenomena.
In the strictest scientific terms, some will say that once a person dies, they cease to exist. The only allowance given is the observation that energy never truly ceases - it continues, in another form perhaps, but it does continue. Those who travel in religious or spiritual circles often believe that this very energy is your soul, or the animating and vital principle in humans as well as all living beings.
At the end of the day, we will all believe (or deny) what we choose. We're not asking you to believe or accept anything - we only ask that you remain open minded.