We all start on even ground. We are all made in God's image. We are all given a soul, body and spirit. We all have extenuating circumstances in life - hard times, abuses, despairs, good times, times of pride and times of humiliation. It's part of the sin nature we're born with. I believe with all my heart the scripture that says, "I [God] take no pleasure in the death of the wicked.", or "God isn't willing that any perish, but that all would come to repentance." Why are some people void of faith? Surely it can't be a circumstantial cause - like personal sin and poor choices (we all have personal sin), environment (we all are born into a fallen world) - and certainly God doesn't choose to inflict misery on certain people. Hardening of the heart? Who hasn't felt bitter and been hardened for a time? And if extended bitterness and hardness is the reason, isn't God's grace bigger than the sin of unbelief? I'm kind of knocking on the doors of Paul's writing in Romans of "Who can thwart God's will? Why does he still find fault? But who are you, O man, who replies to God this way??" My answer is that everyone needs to "try" Jesus. If you never do, you will be making a choice you will regret forever. So I guess the answer to my question is that sin makes people the way they are, but choosing to reject Jesus makes this permanent.