We cannot know that God is real. That is why we call belief in God "faith." If we could prove that God is real, we would not have to have faith anymore than I have to take on faith the fact that my computer or my house or my cat exists.
Many people feel that they know that God is real. They feel that way because they can feel what they believe is God working in their lives. Because we cannot prove the existence of God in any scientific way, this is the most compelling evidence that God exists. But a person's feeling is not proof, it is just a feeling.
So, we cannot know that God is real. We can only have faith that there is a God.
To every creation, there is a creator. So if I am here, there is a Creator - The God.
We can know God is real because God reveals himself to us. There are two ways in which God has chosen to reveal himself. The first is the way in which God reveals himself to all of humankind. This is called natural revelation. God reveals himself through His work of creation. The natural world exhibits properties such as order and design that are evidence of a rational Creator. Romans 1:20 says "For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made."
The second way in which God reveals himself is through special revelation. God speaks in special ways and this has been recorded through the witness of people. As witness in a law court provide evidence, so also witnesses through the ages have provided testimony to the existence of God. Hebrews 1:1-2 says "Long ago, at many times and in many ways, God spoke to our fathers by the prophets, but in these last days he has spoken to us by his Son, whom he appointed the heir of all things, through whom also he created the world."
Faith is trusting in these evidences, but is not believing without evidence.
Of Course God is there. He is but One. The True just Creator. He is there always there.. A man cannot come jut like that. look how complex the human body is.. you will find out one day...Believe or don't believe..You cannnot deny His Existence.. He knows what you do and is fully aware of everything