If you read the Bible and believe what it says is true to you or to reality, then does that mean you can go to heaven in the afterlife, even if you had not been baptized? What happens if someone murdered you before your baptism (for whatever reason or negligent manslaughter), so you never actually become baptized? You may believe in God and that the Bible is true and you have repented of your former sins, but you are just not baptized with water.