Romans 10:5-7 For Moses described the righteousness which is of the law, That the man which does those things shall live by them. But the righteousness which is of faith speaks on this wise, Say not in thine heart, Who shall ascend into heaven? (that is, to bring Christ down from above:) Or, Who shall descend into the deep? (that is, to bring up Christ again from the dead.)
‘That the man which does those things shall live by them’ – perfect obedience was required by the law. Since no man could accomplish this, all people were condemned by the law and cursed by it (Deut. 27:26; Gal. 3:10-13; Rom. 3:19-20). This shows the impossibility of being saved by the law and the fact that all can be saved by the gospel (10:6-13).
‘But the righteousness which is of faith speaks on this wise, Say not in thine heart, Who shall ascend into heaven? (that is, to bring Christ down from above)’ Law righteousness demanded perfect obedience; faith righteousness asks only confession of sins and surrender to God who, by the Holy Spirit, sets free from the law of sin and death (8:2), transforms the nature and life (1Cor. 6:11; 2Cor. 5:17-18), fulfils in man the righteousness of the law (8:3), and makes man righteous in Christ (4:1-25; 10:6-13; 1Cor. 1:30; 2Cor. 5:21;).
‘Who shall ascend into heaven? … Or, Who shall descend into the deep? … But what said it?’ This is quoted from Deuteronomy 30:12-14. Paul here simply shows that people do not have to search for Christ or the Word of the gospel, for it is near them and only needs to be acted upon. It is like the law in Deuteronomy 30:12-14: they did not have to search for it; they already had it if they would recognize it. So people have the gospel that will save their souls if they will accept it.
‘Deep’ [Greek: abussos] meaning bottomless, unbounded by any definite known limits. Christ did descend into the lower parts of the earth to liberate the righteous dead and take them with Him when He ascended on high (Matt. 12:40; Eph. 4:8-10; Heb. 2:14-15).