Romans 10:9-11

 9 ...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. 
10 For it is with your heart that you believe and are justified, 
   and it is with your mouth that you confess and are saved. 
11 As the Scripture says, "Anyone who trusts in him will never 
   be put to shame."