Allah made everything in pairs, including this life. Allah mentions the day and the night. He mentions the sky and He paired the sky with a brilliant lamp, the sun.
So when we think of this life, why do we not assume He also made it as a pair? Our existence has been made in pairs. Allah shows us that in His creative style, He made everything in pairs even our souls.
Allah is a manufacturer and His signature brand is making things in pairs. Allah made this life and He made a life for us after.