With Fake news all around us, and the pandemic challenging our deepest beliefs, even trust in science, more than ever we need truth. This blog grapples with the deepest of questions. "How do I know?". We fearlessly sweep through foundations of experimental science and probability, neuroscience of our senses, psychology of the brain, artificial intelligence, quantum physics of what can be known, before we boldly address the mathematics of infinity and ultimately 'how do I know there is a God?'