Occasionally, God may give some people a glimpse of heaven, although I believe such instances are rare, and need to be treated with caution. The Apostle Paul told of someone (probably himself) who was allowed to experience heaven's glory (see 2 Corinthians 12:2).
Our proof of heaven, however, doesn't depend on alleged reports; at best, they can only confirm what God has already told us in His Word, the Bible. Instead, our assurance of heaven depends solely on the promises God has given us in His Word. From one end of the Bible to the other, we're reminded that we weren't meant for this world alone, but we were meant to live in God's presence forever. The Bible says, "Our citizenship is in heaven" (Philippians 3:20).
How do we know those promises are true? Ultimately, we know it because Jesus Christ rose from the dead. Think of it this way. The only way we could know for sure that heaven exists would be for someone to die and go there -- and then come back to life and tell us about it. And that's exactly what Jesus did. By His death and resurrection Jesus Christ overcame death, our final enemy. Jesus' promise is true: "I am the resurrection and the life. He who believes in me will live, even though he dies" (John 11:25).
Put your faith and trust in Jesus Christ, for He alone can assure us of eternal life. Then put your faith into action by following and serving Him every day.