This is another of the useless things religious people (not only Christians) like to say to atheists. And I don't mean "useless" in the sarcastic, pejorative sense. It's simply without purpose. There is no benefit anyone can gain from hearing it, no action anyone can take on it. In absolutely every story I have heard of God revealing himself to someone, the experience described is absolutely compatible with two competing explanations: Divine Revelation, or mild hallucination. OK, maybe not-so-mild in some of the more outlandish stories. But often enough, the evidence of the godly is as scant as, "I had a warm happy feeling in my heart."
A principle I follow in evaluating the world around me is, when two competing explanations satisfactorily fit the available evidence, choose the one that requires fewer unsupported assumptions. This is my personal version of Occam's Razor. So when I hear these personal testimony stories I look at the evidence. I will take the tellers at their word that they really did have a warm feeling, and accept that as a fact. But their leap to explain that as a divine revelation leaves me standing still. I'm always, in these cases, going to go with: "You arrived at an emotional state where you expected a warm feeling, and lo, you had a warm feeling. That entire process is very easy to understand as taking place entirely between your ears."
I do many things, and have many experiences that leave me with a warm feeling. Not one of them has additional attributes that are only consistent with an omnipresent, omniscient, omnibenevolent being who wrote a really ambiguous book about how I should live and wants me to stone LGBTQ people but also gets really pissed if I eat crab cakes.
This #2 of a series covering the top ten goofy things religious people say to atheists. Earlier: