I’ve always liked the description of faith not as believing something despite all evidence to the contrary, or believing something that conflicts with logic. That’s just stupidity.
To me, faith is continuing to act on a belief you formed using your full logical powers in a moment when emotion tempts you to do otherwise. It’s faith in your own ability to arrive at a sound conclusion, and faith in your former resolve to stick with it even when it becomes costly.
When you commit to diet or exercise or daily blogging, if you do so for sound reasons based on real knowledge of yourself, your goals, and a causal connection between those activities and your desired outcomes, you will need faith to stick with it. There will be moments and days when the little voice says, “What’s the point of all this anyway?” or “One day off won’t hurt anything”. In that moment, you won’t have a clear rejoinder. You might be tired or drunk or angry, rendering your reasoning faculties sub-optimal.
It is in that moment that you need faith. You must act on a firm belief that at the time you set the challenge before yourself, you were thinking clearly and you do have good reasons, even if not readily accessible in the height of emotion.
Faith is pro-reason, not anti-reason.