Fear

The fear of the LORD is the beginning of knowledge - Proverbs 1:7a

Several years ago my son, Elijah, did something that upset me. In my anger I yelled out his name. Often when we are afraid we run or try to hide. It is a natural human reaction to flee from what scares us. However, Elijah did something I did not expect. After hearing my shout Elijah did not run away from me; rather he ran to me.
The Christian life begins with fear. The proper response of a sinner with the knowledge of a holy, righteous God is complete and utter terror. We can do two things with that terror. We can try to hide our sin by justifying our own actions, imagining that we are innocent, ignoring our condition or by trying to keep certain things from God (as foolish as this is). Or we can run to Him admitting our brokenness and wrongdoings and throwing ourselves on His mercy.
It is the one who runs to God who finds His mercy. And in that mercy our fear evaporates.