LAW - GRACE

1 Corinthians 15:56 NIV

The sting of death is sin, and the power of sin is the law.

The Law is good, but it is not complete. Even though it gives us the knowledge of what is Good and about Sin. It doesn't give us strength to overcome the Sin, Only Grace of God does that. 

Paul said: In 2 Corinthians 12:7-9 King James Version (KJV)

7 And lest I should be exalted above measure through the abundance of the revelations, there was given to me a thorn in the flesh, the messenger of Satan to buffet me, lest I should be exalted above measure.

8 For this thing I besought the Lord thrice, that it might depart from me.

9 And he said unto me, My grace is sufficient for thee: for my strength is made perfect in weakness. Most gladly therefore will I rather glory in my infirmities, that the power of Christ may rest upon me.

Romans 5:20 NIV

The law was brought in so that the trespass might increase. But where sin increased, grace increased all the more,

We cannot be Holy by our doings. So, we need Jesus Christ.

We cannot be perfect with Law, but with Grace.

We cannot overcome Sin by our strength, but by the Power of Christ - His Grace.

Romans 6:14 NIV

For sin shall no longer be your master, because you are not under the law, but under grace.

What does the Law do? Law condemns with what we are in natural. Grace doesn't condemns as it looks our spiritual being. There is no aspect of Love in Law, its just justification and fear. But with Grace, God's Love with covers all the sins and there is no fear in such perfect love.