Having shown what justification is Paul went on to reaffirm that it is available only by faith. He proceeded to expound the great theological thesis of 3:21-26. Verses 27-31 state this theme, and chapter 4 elucidates and elaborates it.
3:27-28 There is no place for human boasting in this plan of salvation (cf. Eph. 2:8-9), though the Jews were inclined to boast because of their privileges (2:17, 23). The reason is that God's provision of salvation by faith springs from a different law than salvation by works does.
"One would think that the sinner would love to be forgiven at no cost. Unfortunately that is not the case. After all, sinners have their pride. They desperately want to claim some role in their own redemption."112
Salvation by works rests on keeping the Mosaic Law. This does not mean that the Mosaic Law required works for salvation but that those who hope to earn salvation by their works look to the Mosaic Law as what God requires. God's gift of salvation, however, rests on a different law (principle) that God has also ordained and revealed. This "law"is that salvation becomes ours by faith in Jesus Christ. Faith is what God requires, not works.
". . . He hassent His Son, who hasborne sin for you. You do not look to Christ to do something to save you: He has done itat the cross. You simply receive God's testimony as true, setting your seal thereto. (I often quote I Timothy 1.15 to inquiring sinners: Christ Jesus came into the world to save sinners.' In response to my question, they confess that came' is in the past tense. Then I say, How sad that you and I were not there, so that He might have saved us, for He has now gone back to heaven!' This shuts them up to contemplate the work Christ finished when He was here;upon which work, and God's Word concerning it, sinners must rest: that is faith.) You rest in God's Word regarding Christ and His work for you. You rest in Christ's shed blood."113
3:29-30 Paul continued to appeal to his Jewish audience in these verses as in the former two. If justification is by the Law, God must be the God of the Jews only since God only gave the Law to the Jews. Paul's point was that there are not two ways of salvation, one for the Jews by works and the other for Gentiles by faith. This is only logical, he reasoned, since there is only one God who is the God of all humankind. Paul probably used two separate prepositions in verse 30 ("by,"ek, and "through,"dia) simply for literary variety.114His point was that there is only one method of obtaining God's righteousness.115
3:31 Paul was not saying that the Law is valueless.116Even though he believed in salvation by faith he saw the Law as having an important function. Probably Paul meant that its function is to convict people of their inability to gain acceptance with God by their own works (vv. 19-20).117The Law is not something God has given people to obey so they can obtain righteousness. Man's inability to save himself required the provision of a Savior from God. The Law in a sense made Jesus Christ's death necessary (vv. 24-25).
The point of verses 27-31 is that justification must come to all people by faith alone. Paul clarified here that this fact excludes boasting (vv. 27-28). It is also logical in view of the sovereignty of God (vv. 29-30), and it does not vitiate the Mosaic Law (v. 31).
