The law that teaches us not to covert is one which gives us a key to understand how to understand the law and to shaping our desires so that they might being harmony in our lives.
If you avoid the cross it really doesn't matter what you worship because the rejection of the cross leaves you on the side of the prince of this world on the day of judgment
Grace has been given so that we might live a new life and have the benefit of God's wisdom to do good. It was never intended as a license to act like slaves to sin.
We don't need to understand ourselves or cure ourselves of the human condition when we are in the hands of the one who understands us best and loves us most.