The answer is: Nature and creation

John 5:31-47

In the Gospel of John, the theme of witness is woven intricately throughout its fabric, reflected in multiple testimonies about Jesus. While we see human witnesses like John the Baptist and Jesus' own works pointing to his divine mission, nature and creation serve as a backdrop to this larger story, without standing in the witness box themselves.

Interestingly, the Bible often hints at creation as an indicator of divine truth. For instance, in Romans 1:20, it's noted that God's invisible qualities have been "clearly seen" in what has been made; creation whispers of His existence and glory. Yet, here John takes a fascinating route by stripping away the direct testimonies from nature, focusing more on human accountability and the ways in which people respond (or fail to respond) to the call understood within those testimonies.

This gospel elevates the importance of belief and personal acceptance over observance—everyone's experience is uniquely shared through their interpretations of the signs and wonders around them. Plus, let's not forget the fun fact that the Gospel of John is often seen as more mystical, even poetic, in its storytelling when compared to, say, the synoptic gospels. John embodies that deep philosophical tone, introducing concepts with layers—just like creations around us. It begs us to explore what the world reveals and how we, too, can be witnesses to truth in our interactions with that world, igniting our curiosity along our spiritual explorations!