If nothing else, one reason we need to believe in Jesus is because God's Word, the Bible, tells us to believe in Him. Jesus said, "Let not your heart be troubled; you believe in God, believe also in Me" (John 14:1, NKJV).
But why does the Bible tell us to believe in Jesus as well as in God? One reason is because of who Jesus was: He was God in human flesh. In a few weeks, we'll be celebrating Christmas -- and the reason we celebrate it is because on that first Christmas night God took on human flesh and became a man. Think of it: God became a man! This is why Jesus could say, "Anyone who has seen me has seen the Father" (John 14:9).
But we also need to believe in Jesus because of what He did: He became the final and complete sacrifice for our sins. Only one thing separates us from God, and that is our sin. How can our sins be erased? Only God can do it -- and He did it by placing all our sins on Christ when He died on the cross for us. He was without sin -- but on the cross He took the judgment we deserved. Because of Him, the Bible says, "There is now no condemnation for those who are in Christ Jesus" (Romans 8:1).
What does it mean to believe in Jesus? It doesn't just mean that we believe He existed, or even that He died and rose again from the dead. It means also that we trust Him and commit our lives to Him. Turn to Christ and ask Him to forgive you and come into your life today -- and He will.