Romans 10:10 note 1 (RcV)

Romans 10:10
For ¹with the heart there is believing unto righteousness, and ¹with the mouth there is confession unto salvation.

10¹ To believe with the heart is toward God; to confess with the mouth is toward man. To believe with the heart is to believe in Christ, who was glorified and raised by God from the dead; to confess with the mouth is to confess that Jesus, who was despised and rejected by man, is Lord. Both are conditions for our being justified and saved.