There will not be night in the New Jerusalem  -  Revelation 22:5

And there shall be no night there; and they need no candle, neither light of the sun; for the Lord God giveth them light: and they shall reign for ever and ever.

In the New Jerusalem, there will not be candles or the light of the sun, as they are not needed. The only light there is the light that God provides. Due to the fact that there is no night and Jesus is the light of the city, there will be no fear in this city as well.