I'm sure one reason your friend says this is because he has made Jesus Christ the foundation of his life, and he knows this is not what Jesus taught.
Instead, Jesus taught that heaven is real, and that all who go there will still be individuals. We were each made in the image of God, and we each have a soul or spirit that will live on after we die. And someday, when God's plan is complete, we each will be given new bodies, and we each will live forever in the presence of God. This is one of Jesus' most comforting promises, for it assures us not only of our survival after death but also our reunion with those who have gone to heaven before us.
Jesus promised, "I am the resurrection and the life. He who believes in me will live, even though he dies" (John 11:25). We can trust this promise because Jesus was the Son of God, sent from heaven to open heaven's door for us. And He proved His promise was true by dying and then rising again from the dead.
I invite you to discover what your Christian friend has discovered: the joy and hope of Christ in the face of death. Don't follow a road that ends only in despair and hopelessness, but open your heart to Christ and put your trust in Him. When we give our lives to Him, "We have this hope as an anchor for the soul, firm and secure" (Hebrews 6:19).