“Cursed is the man who does not obey the words of this covenant which I commanded your fathers in the day I brought them out of the land of Egypt” (Jeremiah 11:3-4 NKJV).

The Lord reminded Jeremiah that the Mosaic Covenant was conditional. It contained both blessing and curse that was conditional upon their obedience to the law. Obeying the law, they were under its blessing. Disobeying the law, they came under its curse. Israel was unable to obey the law, so they fell under the curse of the law.
However, the Abrahamic Covenant was unconditional. God gave it freely by His grace. It was based on God’s promise, not God’s law. The promise preceded the law and was given for salvation, but the law was given “because of transgressions” (Gal. 3:19). This covenantal promise was given to Abraham that in his “Seed all the nations of the earth shall be blessed” (Gen. 22:18). The apostle Paul said that this “Seed” is Christ (Gal. 3:16).
A promise must be believed to be received, but a law must be obeyed. Yet, both the promise and the law were fulfilled in Christ Jesus. For He who knew no sin, became sin for us and has “redeemed us from the curse of the law” by becoming accursed Himself (Gal. 3:13). Christ has taken our curse that we might receive His blessing.
The promise reveals God’s GRACE, but the law reveals our GUILT. So, let us rejoice and be glad that the blessing of salvation depends on God’s PROMISE, not our PERFORMANCE!