“From the very first day, we were there, taking it all in - we heard it with our own ears, saw it with our own eyes, verified it with our own hands. The Word of Life (Jesus) appeared right before our eyes; we saw it happen! And now we’re telling you in most sober prose that what we witnessed was incredibly, this: The infinite Life of God himself took shape before us. We saw it, we heard it, and now we’re telling you so you can experience it along with us, this communion with the Father and his Son, Jesus Christ. This, in essence, is the message we heard from Christ and are passing on to you: "God is light, pure light; there’s not a trace of darkness in him."” 1st John 1: 1-5
Atheists of course say that the Apostle John is lying through his teeth about knowing Jesus. How much less can they accept that God is light, in Him there is no darkness? Centuries before John lived, the Psalmist also knew God in this context. "You [God] are a lamp for my feet, a light to illuminate my path."
This is something with which all Christians can identify. The Psalmist was using a metaphor that people in that time could easily identify with. Walking along a mountainous path in the dark was treacherous. No less so than trying to navigate life itself. Being able to trust Jesus, our Creator as to how best live our lives is a wonderful release from worry.
The Joy that I experience because of my walk with Jesus, my trust in Jesus, my faith in Jesus is all out of proportion to the circumstances of my life. I know Him in whom I believe and I declare, along with John that Jesus is absolutely trustworthy. He will never steer you wrong.