How is 卻 & 接受 used in John 1:5 CUV?
卻 in this context means 'however' or 'but', serves to connect the two phrases.

光照在黑暗裡 (The light shines in the dark)，黑暗不接受光 (the dark does not receive the light.)

光照在黑暗裡，黑暗[卻]不接受光 (The light shines in the darkness, [however], the darkness does not receive the light)