How do we know salvation is through perfect obedience?

In Luke 10, Jesus affirms that eternal life hinges on perfect and complete obedience to God's commandments. When asked by a lawyer what one must do to inherit eternal life, Jesus directs him to the law. The response highlights the necessity of loving God with all one's heart, soul, strength, and mind, and loving one's neighbor as oneself. Here, we see that salvation is based on a standard of perfect obedience that no human can achieve on their own, reinforcing the necessity of grace through faith in Christ's fulfillment of the law on behalf of sinners.