Romans 10:9-10 (NIV)
That 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.
Believing that Jesus died on a cross and was buried is believing nothing more than what has happened to many thousands of men before and since. But believing that Jesus was resurrected from the dead is to believe that his death was effective to accomplish salvation for those who would believe. Also notice that this believe is not head knowledge but the Bible calls it knowing with the heart. This is deeper then mere mental assent to the facts. How much deeper is it? Notice the confession "Jesus is Lord." It is that deep, deep enough to trust Jesus with your whole life and make him the ruler over it, that is to make Him Lord of your life. If you will believe what Jesus said is true then because of the shear magnitude of his sayings, you will by definition of your having believed it, become subject to his words demands. If you do not make him Lord, then it is impossible for you to say that you believe him.
Here is my confession:
I am a sinner. My sin was deserving of God's wrath. I believe Jesus died for my sins. I believe his words are true, proven when God raised him from the dead. He is Lord of my life. I will follow him. I am justified before God. I am saved from his wrath. Hallelujah!