It is written that you have proof of God's existence through what has been made. The creation and all it's designed functions. It's such indisputable proof that in the book of Romans it states that those who do not believe are without excuse. I believe that God is real by faith, but also by the proof that I see all around us. People can choose to be willfully blind to his existence. But must be prepared to accept the consequences of that thinking pattern. But on the day you stand before him and claim you had no proof he was real, his book that states "without excuse" will come into play. Good luck to you.