Since God is sinless it makes sense that He desires for us to be more like Him.  God desires for us to not just have knowledge of His word but to be better obedient to Him because of what His word has taught us. “Ye are my friends, if ye do whatsoever I command you. – John 15:4” In contrast Romans 3:20 God makes it clear that we are not saved by obeying the law but instead by the blood of Christ. I love the book of Romans because it helps me further understand the extent of God’s forgiveness, mercy and love by teaching me that regardless of what we have done we can always come to Christ and He will wipe our slate clean and reconcile us to God the Father through His blood on the cross.