During the debate between Bill Nye (The Science Guy) and Ken Ham (the Not-So-Science Guy) regarding creationism and evolution, the moderator asked each of them the following question: “What, if anything, would ever change your mind?”
In short, Ken Ham answered, “… no one is ever going to convince me that the word of God is not true.”, while Bill Nye’s response was along the lines of “show me just one piece of evidence, and you’ll change me immediately.”
That is the fundamental difference between science and faith.
Science requires reliable evidence to demonstrate that something might be true. Faith does not require any evidence and even rejects it if it contradicts one’s beliefs.
Sam Harris has the same opinion, but says it much more eloquently:
Water is two parts hydrogen and one part oxygen. What if someone says, “Well, that’s not how I choose to think about water.”? All we can do is appeal to scientific values. And if he doesn’t share those values, the conversation is over. If someone doesn’t value evidence, what evidence are you going to provide to prove that they should value it? If someone doesn’t value logic, what logical argument could you provide to show them importance of logic?