10:9 confess … the Lord Jesus. Not a simple acknowledgment that He is God and the Lord of the universe, since even demons acknowledge that to be true (James 2:19). This is the deep personal conviction, without reservation, that Jesus is that person’s own master or sovereign. This phrase includes repenting from sin, trusting in Jesus for salvation, and submitting to Him as Lord. This is the volitional element of faith (see note on 1:16). believe in your heart. See note on 1:16. God has raised Him from the dead. Christ’s resurrection was the supreme validation of His ministry (cf. John 2:18–21). Belief in it is necessary for salvation because it proved that Christ is who He claimed to be and that the Father had accepted His sacrifice in the place of sinners (4:24; cf. Acts 13:32, 33; 1 Pet. 1:3, 4). Without the resurrection, there is no salvation (1 Cor. 15:14–17). See note on 1:4. will be saved. See note on 1:16.

10:10 confession. This Gr. word basically means to say the same thing, or to be in agreement with someone. The person who confesses Jesus as Lord (v. 9), agrees with the Father’s declaration that Jesus is Savior and Lord.
10:11 Quoted from Is. 28:16 and 49:23. This quotation not only demonstrates that salvation by grace through faith alone has always been God’s salvation plan, but that no one—including Gentiles—was ever to be excluded (1:16; 3:21, 22; 2 Pet. 3:9; see also Jon. 3:5).
Gr. Greek
MacArthur, John Jr: The MacArthur Study Bible. electronic ed. Nashville : Word Pub., 1997, c1997, S. Ro 10:9