This sentence "God alone exists, the question to ask is whether 'I' exist?" is worth contemplating upon. This sentence mentions two different entities: God is the only existing truth and the 'I' is the false identity, but appears real.
Who do we think we are? The body, the mind, or the constant entity, the Self, Consciousness, God within the body-mind? Let's understand this topic with an example.
One day John came to his friend Sam and pleaded to let him stay in his house as he had gone bankrupt and lost everything. Sam agreed at once. "Why not? You are my best friend. You can live with me as long as you want." A few days later it so happened that John met with a terrible accident. He lost an eye, a leg, and an arm. Even under such circumstances, Sam insisted on keeping his friend in his house.
Unfortunately, within a week, John passed away due to his sufferings. Sam arranged for a proper burial of his best friend's body. The moment he stepped in his house, his little son asked him, "Why didn't you keep your friend even after he is dead?" Sam replied, "How can I keep a dead body in our house?" So, the question arises: Who was Sam keeping with him, saying he's his best friend? John's body? If that's so, then it was present even after his death; yet it was not deemed fit to continue keeping it in the house. Then was it the life, the Consciousness, the Self, the God within John's body that was Sam's friend? That's the only possibility. Everything feels alive and lovable only due to the presence of the Self within the form.
This contemplation can help us reach greater heights of understanding and ultimately lead us to the actual state of our "being". The mind creates an illusory layer of the pseudo 'I', which gives us the impression that it's only the body-mind that exists. For thousands of years even science believed only in matter because "Seeing is believing." But Consciousness or God's presence is felt when we start believing. The more we believe, the more clearly we start seeing the presence of the Almighty in each and every thing in nature.
The body comes into existence in the frame of time and space, i.e. when we wake up from sleep. What happens in deep sleep? Do we feel the presence of our body and mind? No. Then who is the one that says, "I had great sleep last night" Who was awake and watching? The one awake in our deepest slumber is also awake in our active state during daytime.
What is GOD? An acronym for the one who generates, operates, and destroys. So, there is someone or something that is the creator or source of everything - living and non-living. And the interesting truth is that the Creator is experiencing and expressing itself through all these various forms.
The limitation of words is the biggest hindrance to gain the ultimate knowledge of the infinite. Words can create confusion in understanding the false and the real identities and the mind defines the everlasting existence into something in limitation. Contemplation is the only path that will clear the muddy turbulent waters of confusion and ignorance into crystal clear and calm waters of understanding the higher consciousness. A simple experiment will make us reach the higher levels of understanding.
Let us close our eyes and imagine that all the things surrounding us are disappearing or getting dissolved - the chair we are sitting on, or the bed, the room we are in, the house we live in, the neighbourhood, the streets, the suburb, the district, the state, the country, the world, the earth, the universe. Now our body parts are slowly disappearing like our legs, trunk, arms, neck, mouth, nose, ears, eyes, the whole face, the whole body. Now the thoughts are getting dissolved. What remains at last? Nothing. Absolutely right, Nothing remains. But there is someone who is still present and watching the Nothingness. You can eliminate everything else, but not the one who is watching this nothingness. That is the REAL 'I' , also known as God, Lord, Almighty, Self, Consciousness.