In scriptures, many times faith is referred to as a belief in action, it is easy to believe that there is a God, but it is by faith you put your belief in action and walk the Christian walk (or what ever spiritual beliefs you choose to uphold)..
How do those acting to, for example, help others in need through their faith in action help us to believe that a God exists? I suggest that it is those who help others without the belief in a God that we should especially look up to because they act without expecting a reward such as eternal life.
