Law and grace cannot co-exist. The one keeps the Christian in bondage, the other sets us free from bondage.
Neither can the Law give victory over sin. Sanctification is through the Spirit, not the Law. Any growth in our Christian life, or any enhancement of our Christian character is produced by the Holy Spirit, not by self-effort.
What is it that sets us free? “For in Christ Jesus neither circumcision (living by the law) availeth any thing, nor uncircumcision, but a new creature.” Realizing we are new creations is what brings us peace and mercy!