An real life example in discussion is to switch on the light. Do you need to study all electrical knowledge behind the switch in order to turn on the light? No, you just need to know the procedure (faith) and trust that it will works. Then, if you interested, you will look into it in how to change the bulb, configure plug and get more knowledge
about wire etc. This will build your knowledge on what you belief (turn on the light). If you prefer to study everything before practice, you might be in darkness until the time you take into action.