For the law was given through Moses; grace and truth came through Jesus Christ. John marks a turning point: the law came through Moses, but grace and truth came through Jesus. Two different systems, two different ages.
Fear lives from the law: "Do this, do that, or else..." But grace and truth live from love. In the New Covenant you are no longer under the rule system but under grace. And grace makes you brave, because you are loved before you do anything.