The relationship one has with God, is very much in the realm of how it feels when you know you love someone. It's not tangible and it's not a physical force of any sort.
It is a feeling...it is an experience. But to pinpoint moments in time when you "fell in love" with God (as you would in a relationship with someone else on earth), is impossible.
It is an exchange that is felt in the heart and it is imprinted in the mind to never forget. The moment a person gets their affirmation that God is true and real - it is a feeling that is beyond description. It is a sensation that only someone can experience themselves.
Imagine if you studied for a test, and you just knew - without knowing what answers where on the test, that you would pass and get 100%. You just know it because you did your homework and you did it with the goal to not only pass, but to reach the perfect score.
Imagine that feeling of "knowing," and multiply that by a million and infinity. It's a feeling that not any Christian can deny - even under the compulsion that if we don't do so, we'd be executed.
It's not the god can't exist - it's that you have to experience it yourself, or you don't. And with that - no one is asking for you to lean on my experience to "save" you. It really is something you should do for yourself because you want to. But with receiving this confirmation - you really have a lifestyle change to follow Jesus Christ all your life.