I have a heart of stone...

The religious always introduce some terms which I cannot understand. One of this is "soul". Another is many religious accuse atheists, like me, have a "heart of stone" and cannot accept their gospel. How can I soften my heart to accept non-sensible ideas?

A commenter on Ray Comfort's blog post this:

My question is specifically, what made/makes you able to soften your heart and let the God in and not me? Is it a physical, biological, mental mechanism that is holding me back, or is it a spiritual issue i.e., my soul.

If it's the former, what is it? A brain tumor? A pituitary issue? Hammer toe? Lack of natural rhythm?

Or if it's the latter, my soul. How does that work? Why does my soul cause me to reject God? What controls my soul? Are we all a completely blank slate when we are born and our souls are shaped by experience? How does my brain interact with my soul? What are the defining features that all souls share, and what features are individual to me?
If I am not a blank soul, what is my starting state? What do I(everyone) inherently have and what do I acquire over the course of my life? Clearly, if this is the case, I did not start with a inherent belief in God, as I have never believed, as far back as I can remember, I have been a non believer. My parents are believers, all of our neighbors and friends etc ... So you can't say I was brain washed into my non belief. Where did my lack of belief come from? If it was there from the beginning, it's not my fault, it is part of soul. If it's something I learned, why is my soul capable of non belief and what is my soul missing that yours isn't that would allow me to come over to your side?