I'm thankful you've taken the time to write and ask this question - because the most important decision you will ever make is where you will spend eternity. The Bible warns, "How shall we escape if we ignore such a great salvation?" (Hebrews 2:3). What you've heard is right: All we have to do to get into heaven is to believe in Jesus. Jesus Himself said, "Whoever believes in the Son has eternal life" (John 3:36). But what does it mean to "believe" in Jesus? Does that mean simply to believe that He existed, or even that He came down from heaven to save us?
No, to believe in Jesus means far more than this. It means first of all that we understand who He is: the only Son of God, sent from heaven to save us from our sins. It means we also understand what He did for us: He died on the cross to take away our sins. The Bible says, "This is love: not that we loved God, but that he loved us and sent his Son as an atoning sacrifice for our sins" (1 John 4:10).
But to believe in Jesus also means to trust Him as our Savior, and commit our lives to Him as our Lord. In other words, to believe in Jesus is to turn our lives over to Him - completely and without reserve. And this is what I urge you to do. By a simple prayer of faith commit your life to Jesus Christ today.