Mosaic law
I was reading an answer published under topical Q&A here about Mosaic law. Here’s a line from it that specifically brought a question to mind: “The Mosaic Law had limited purpose and duration. Its obligations ended when Jesus Christ came into our world as the fulfillment of all the prophecies of the Messiah.” Of course the people of the Old Testament were no more capable than we are of keeping God's laws perfectly, and if I’m correct, it was their faith in the coming Savior, and God’s promise of that, that saved them, whereas now it’s faith in Jesus who has already come and died for our sins. I know that good works and keeping God’s law are the fruits of saving faith and evidence for it. But when it says “its obligations ended,” that seems to imply there once was an obligation to keep God's law for salvation and now there isn’t. How was that different for them vs. how it is for us now? Thanks.
The implication that “there was once an obligation to keep God’s law for salvation and now there isn’t” is not accurate. God’s law points out sin and the need for a Savior (Romans 3:20). The gospel is the good news of salvation (Romans 1:16). Salvation has always been through faith in the gospel message of the Savior and not performance of the law.
The Mosaic Law, given to the people of Israel, contained civil, ceremonial and moral laws. Those laws governed the people of Israel. The people were not free to obey or disregard them; they were obligated to obey them. That obligation did not mean that their performance of the law was contributing to their salvation. No, you noted correctly that “it was their faith in the coming Savior, and God’s promise of that, that saved them.”
Once Jesus came into the world and fulfilled the prophecies of the Messiah, the ceremonial laws in the Mosaic law became obsolete (Colossians 2:16-17). Likewise, the civil laws that governed the Old Testament nation of Israel, as God constituted it for the purpose of bringing the Messiah into the world, are no longer in effect (Galatians 3:22-25). What remains from the Mosaic law is the moral law—God’s will for all people of all time.
I hope this clarifies matters for you.