Our religious self-satisfaction falls apart in at least two ways. First, we never obey all of God’s law. Before Jesus this difficulty was focused on the over 600 different commands in the old Testament. Keeping in mind and actually doing them all was considered such a difficult thing that only a few even attempted it.
After Jesus, and His sermon on the mound, it became apparent God desired an inward obedience to the law which is far more difficult than an outward one. Its not enough to abandon murder, you may not hate in your heart. It is not enough to keep yourself from adultery, you may not even look with lust. Each commandment is a way into the heart.
Even if we were to obey the law perfectly we would still fall short in our attitudes and thoughts. Paul illustrates how Jesus firmly moved being good from the sphere of receiving public notice for our scrupulous nit picking behavior to the intimacy of our personal relationship with God.
So the question is, how do we do good in such a way that our hearts, and not just our actions, are changed for the better?