This work is focused on the interconnections between evidence, knowledge, and justification. I defend here the following theses. All evidence that we have is knowledge. All knowledge that we have is evidence. A piece of evidence supports a proposition p just in case it raises p's probability. A justified belief is a belief that complies with the fundamental norm of belief. The fundamental norm of belief is: one ought to believe that p if and only if one knows that p. It is not the case that one's belief that p is epistemically justified if and only if one's total evidence supports p and one's belief that p is appropriately based on one's evidence. Nevertheless, if one's belief that p is epistemically justified then one's total evidence supports p and one's belief that p is appropriately based on one's evidence. The present thesis comprises a detailed defence of these claims.