Catholics believe that death "is the separation of body and soul the body decays, while the soul goes to meet God and waits to be reunited with it's risen body on the last day" Youcat 154. But it is not known to be the end of our life. It's just the end of our life on earth. Us humans have free will and live our lives the way we want too. We have full responsibility on how we want to live our lives. Mankind can choose where they would like to go if they don’t want to be with God. God will not force them to be with him and they can go to hell. Which is full absence from God himself "Hell is the condition of everlasting separation from God, the absolute absence of love." Youcat 161 and is permanent you can