Those who attempt to pit the new covenant against the old covenant, or the law of Christ against the law of Moses, because they deem the latter gospel deficient, have not heard its salvation-song as David and the thousands of believers in Israel sang it (Ps. 103). Authors who characterize the old covenant as primarily or wholly law based and the new covenant as primarily or wholly grace based read the old covenant with blinded minds and veiled hearts (2 Cor. 3:12–15).
Paul addressed such misrepresentations head on when he emphatically affirmed that there is only one gospel, “the gospel of Christ,” and that anyone, including Moses or even “an angel from heaven,” who taught a different gospel was to “be accursed” (Gal. 1:7, 8, NKJV). Paul, with other New Testament authors, taught that the God of the Old Testament, Yahweh, was Jesus (compare Joel 2:32 with Romans 10:9–13), the very One who progressively revealed His one and only true gospel through His successive covenants over the ages. The gospel of Moses was “the gospel of Christ.” Hebrews affirms that indeed the gospel that Jesus revealed to “all who came out of Egypt, led by Moses” was the same gospel He gave to New Testament believers: “The gospel was preached to us [in the New Testament era] as well as to them [whom Moses led out of Egypt]” (3:16, 4:2). It is the “everlasting gospel” and has never changed (Rev. 14:6)!
Some point to the 613 laws of the Mosaic covenant as evidence of the old covenant’s obsession with law and obedience in contrast to the New Testament’s emphasis on grace and faith, not taking into account that the Sinaitic covenant included all of the civil laws for the new nation and a detailed manual for priests and the entire ritual system. Old Testament believers loved Yahweh’s law (Ps. 119) because they loved Yahweh as their devoted Father who “knows our frame . . . [and] remembers that we are dust” (Ps. 103:14); they accepted His instruction as His loving guidance to promote and protect their welfare and happiness (Ps. 63:1–8).
Some bristle at Psalm 103’s contingency: the covenant’s benefits apply to “those who fear Him” (vv. 11, 17), “keep His covenant,” and “remember His commandments to do them” (v. 18). Such critics must ignore the many such statements in the New Testament, including Jesus’ testimony that He and the Father love those who love them and keep His commandments (John 14:21); this does not negate His love for the world (John 3:16) but affirms that it matters how one responds to His covenant promises of salvation!
One simply cannot read Psalm 103 without being overwhelmed with the length and depth and breadth of the love and grace of God for every human being. He understands and has deep sympathy for what we are up against. The psalm emotively expresses God’s uncompromising commitment, to the death if need be, to rescue us from the pit and to restore to us everything that was lost in Adam on our behalf. The overtone of Psalm 103 is Jesus’ intense longing to one day speak to us those welcoming words that we long one day to hear: “Well done, good and faithful servant. . . . Enter into the joy of your lord” (Matt. 25:21)!