It may seem reasonable to trust in only those things detectable by the senses. However, upon serious reflection, this position lacks the explanatory power to account for even the most fundamental realities of life.
The viewpoint that “seeing is believing” assumes that all reality is comprised of physical matter. This idea represents a crass form of materialism. In other words, for something to exist, it must be visible. And if it’s visible to the eye, then it must be physical in nature.