Romans 10:9

because if thou shalt confess with thy mouth Jesus as Lord, and shalt believe in thy heart that God raised him from the dead, thou shalt be saved:

'Because' -'giving. proof that the word is nigh' (Vincent p. 115). The confession and faith of this verse correspond with the mouth and heart of the previous verse. One simply needs to confess what they already believe in their heart. To simply submit and acknowledge what God has already said about Jesus (Acts 2:36).

'Confess' -3670. homologeo hom-ol-og-eh'-o; from. compound of the base of 3674 and 3056; to assent, i.e. covenant, acknowledge: -con- (pro-)fess, confession is made, give thanks, promise.. confession is basically the acknowledgment that God is right, what God said about Jesus is absolutely right!

Note: Mere lip confession doesn't save. (Matthew 7:21)

'Jesus as Lord' -all other confessions of Jesus, i.e. Jesus lived, Jesus was. good man, Jesus was. religious teacher, Jesus was. prophet, Jesus is 'a' god, etc... fail to result in salvation. For Jesus claimed to be equal with God (John 5:18), i.e. one equal in honor (Romans 5:23), and equal in attributes or character (Romans 14:8-9).

'that God raised him from the dead' -a faith in Christ that doesn't include. faith in his resurrection, also fails to save. (1 Corinthians 15:14).

Note: Right here we have something necessary for salvation, besides 'mere mental assent'. Paul didn't believe that one was saved at the moment they believed. Even those that advocate 'faith-only', violate their own teaching when they have sinners say. prayer in order to receive Jesus into their hearts.

In his commentary Lenski says, 'The instant. sinner believes, righteousness results'. (p. 657). wonder what he would do with the people in Matthew 7:21 and John 12:42. for both groups were 'believers'.