Fear
The fear of the Lord is the beginning of wisdom.
When we are afraid of God, it's because we are alienated from Him.
When we are close to God, there is no fear.
So the solution to being afraid is to seek God's face.
The law points out our imperfections. The law can not make us perfect. The law, therefore, alienates us from the presence of God, because it condemns us.
The Spirit of the Lord makes us perfect and brings us into God's presence. Adding the law into the perfect redemption of Jesus's blood does not make Jesus's blood any better. Anything we add to perfection makes it no longer perfect. Jesus told us to "be perfect even as your Father in heaven is perfect." Nothing short of perfection can be acceptable. Jesus already achieved perfect redemption for us. Only Jesus can save us and cleanse us. If we add the law to our perfect redemption, we effectively abandon that perfection and choose to be found guilty under the law instead.