This is a comment made on an Orthodox Jewish blog by a Jew that I found interesting and somewhat telling:
Righteousness basically means to “do what is right”. If God “works” the righteousness, it is God’s righteousness, not the persons. The person would not be doing what the person was created for and the person would just be a robot or a puppet or just a mirror incapable of being truly righteous, incapable of being truly obedient, unable to truly love God, and not being a child of God; not really created “in the image of God”. Golden calf’s or idols, such as the sun, have no real power, no mind, etc. If a person does evil, is God working through that person at that time and they were just a puppet, or did they freely choose not to do right? Free just as another chooses to do right.
This came after I made the comment that Abraham was righteous because of his faith in God and not his actions. His actions were righteous as they were in response to his faith and trust in God, but the works in themselves do not make him righteous. This is a sticking point within Christianity as well, but it is one of the main differences between Judaism and Christianity.
As this person pointed out, a person would be incapable of being truly righteous, of being truly obedient, unable to truly love God. This is why we proclaim the need for Jesus. We know that we cannot be truly righteous. We know that once you fail to be obedient, and we are talking about complete obedience, that we will forever fall short of that standard of God.
God gave the Laws to show mankind that they would never be able to be truly righteous apart from God. It is not possible to fully and completely follow the Laws the way they are intended. Animal sacrifices were there to help cover up the sin of man, but the sin was never removed. No sacrifices can be made today, so there is no way to be completely obedient as one of the key components has been removed from the people.
For the Christian, we believe that Jesus was the only person to truly live in obedience to God, as he is God. Jesus is the only perfect sacrifice as he is the only thing that was perfect. Time has shown over and over how a created being cannot be perfect. Only that which creates can live up to the standard of the creator.
We are saved and counted as righteous, not because of what we have done but because of our faith in God.