Sometimes, God's existance cannot be made known by convincing
words. He must be experienced, then you will know he exist.
Just like air, you don't see air, but you know it exists. And
whether you believe it exist or not doesn't change the existance of
air.
Take another example, a person born blind. The person has never
seen light. He can choose to believe there is such thing as light
or choose not to. But the person's belief doesn't change the
existance of light.
Even if the person chose not to believe the existance of light, the
person still gets the benefit of warmth the sun produces.
So too for the creator of air and light. Your belief in God's
existance does not change His existance. He still provide air and
warmth to the un-belief, and that per se is a demonstration of His
love for all mankind. And if you want to really know Him, exercise
your faith and belief that He exist (although you might still be
doubtful) first. The experience of His existance will eventually
follow.
Faith is just like a fan. When switch-on, it lets you experience
air.
The bible says: "draw near to me (God), and i will draw near to
you"