There is a difference between what you officially believe and what you really trust. It can make a big difference in your life choices. It can make a forever difference in where you spend eternity.
God explains in Romans 10:9-10 how you can secure your spot in heaven. "If you confess with your mouth, 'Jesus is Lord,' and believe in your heart that God raised Him from the dead, you will be saved. For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved." The word "saved" is a key word in this verse. It implies that someone's in trouble and in need of rescuing.
The Bible says we are literally dying spiritually because of a killer called sin. Sin isn't about the breaking of rules, it's essentially about who runs your life. We were designed by God to ride in a life that our Creator drives, but we've all decided to drive instead and make Him a passenger. That leads us away from God - facing an eternal death penalty. We need someone to save us, and that's what God's only Son did for us on that cross.
Your eternity comes down to what God calls believing in your heart. Many people believe in their head, agree with the facts about Jesus, and even recognize Him as the Savior. If you ask them if they believe in Jesus, they'll say, "Well, sure." Ultimately, their life trust is really somewhere else.
Maybe that sounds like you, which leads us to a life-or-death challenge from God's Word. 2 Corinthians 13:5 says, "Examine yourselves to see whether you are in the faith; test yourselves. Do you not realize that Christ Jesus is in you - unless, of course, you fail the test?" Do what God says: test yourself. It's eternally important to ensure that you don't miss heaven by eighteen inches, the distance from your head to your heart. It isn't agreement with Jesus that makes you belong to Him; it's a commitment to Him.
Has there been a time when you personally told Jesus Christ that you're placing all your trust in Him to rescue you from your sin, give you a relationship with God, and guarantee you heaven? If you don't know, then there probably hasn't been a time. That could change right now.
Trusting in your religion, goodness, or anyone but Jesus is not enough. He took your hell so He could give you heaven, and right now He's waiting for you to trust Him with your heart.