Moses writes this about the righteousness that is by the law: “The person who does these things will live by them.” But the righteousness that is by faith says: “Do not say in your heart, ‘Who will ascend into heaven?’” (that is, to bring Christ down) “or ‘Who will descend into the deep?’” (that is, to bring Christ up from the dead). But what does it say? “The word is near you; it is in your mouth and in your heart,” that is, the message concerning faith that we proclaim: If you declare 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 profess your faith and are saved.
Romans 10:5-10 (NIV)