Don't ever question if GOD exist.
Its like the yet-to-be-born baby bieng in its Mother's womb questioning the existence of its Mother.
GOD cannot be known
GOD can only be experienced
You see the outer world through senses -
Hear, See, Smell, Touch and Taste
Do you see these senses?
Just because you don't see them
Do you conclude yourself that you don't have any sense?
THINK!!
You can experience these senses through sensory organs. You Hear with Ears, See with Eyes, Smell with Nose, Touch with Skin,
And Taste with Tongue.
Its natural to experience your senses through your sensory organs. In the same way, it is also natural that you can experience GOD within your Heart.
Meditate upon Divine light in your Heart
And Experience GOD.