Before you say no, please explain how the billions of people from different religions all are just as convinced as you are, that their "real" God has entered their heart. If you accept these feelings as proof for "knowing" that your God is real, surely you would have to concede that all Gods are real. Or, maybe they are just feelings that are caused by creating a God in your subconscious. If this isn't the case, where do other God believers get there "God is in my heart" feelings. Does it seem reasonable to assume that real Gods and imaginary Gods cause the exact same feelings?