According to me, there is a positive source of energy, we call it 'God'.
We are growing, plants are growing. Who is responsible for that? Is there any person? Is there any scientist. No the answer is that positive source of energy 'God'.
Shri Krishna said that he had come to Earth as 'human being' so he could not use powers of 'Narayana'. If he used his powers, the war (Mahabharata) would have finished in a day only.
This source responses by giving you confidence that he is with you. Whenever you face any trouble, you have an unknown confidence. Have you ever wonder why God is your first whenever you face any trouble, this is because he creates a new sourse in you.
You feel that if he is with you can overcome any difficult situation, it makes your mind to move ahead
This is how we can feel his existence.