By God’s original design, eternal life was to be attained through personal, entire, exact, and perpetual obedience to His law. This standard, established in His covenant with Adam, remains the only path to eternal life.
Although since the Fall we can no longer meet this perfect standard, nevertheless, we are still saved on the basis of perfect law-keeping, but it is not our own. Our salvation rests entirely on the perfect obedience of Jesus Christ—the one who personally, entirely, exactly, and perpetually obeyed God’s law on our behalf. Therefore, our only hope for eternal life is through faith in Him.