A philosophy becomes a conviction through a sort of vetting process. We raise it up from the realm of other dogmas and theories and try it on. We think and wrestle with it until it either resonates or doesn't. When genuinely convinced of its merit, our conviction guides us and our actions and keeps us pointed in a direction we return to in moments of distress and disappointment. It brings comfort and calm when we have chosen and experienced its power ourselves.
Surprisingly, a synonym for conviction is certainty... so why are we encouraging a CONVICTION frame in a method that champions the possibility that is brought about by uncertainty? Without a code, belief, or value system (call it what you will) about why and how you are going about your uncertainty possibilities you will sell out or misinvent in the face of fatigue, competition, or any other setback. Conviction has gotten a lot of people through and over a lot of hurdles.
Don't worry. Religion is not required and the conviction doesn't have to be something you have an expert knowledge of. It can be a mixture of things that inspire and speak to you but it must be your own mixture--you can't borrow someone else's philosophy when the going gets rough.