Sin and forgiveness, post-theism

A friend's post this morning conspired in perfect timing with my own ruminating over life, expectations, disappointments, and moving ahead in a positive direction.

His query involved self-loathing as an unavoidable outcome of not living out the salvation his Creator gave him. I responded with a call to look into the root cause of self-loathing and indicated that believing you are depraved, unworthy, and sinful from birth could lead to such self-loathing. 

My counter-query is this: Do we all need a savior, even those of us who no longer have faith based in theism? I'm beginning to think the answer is yes. 

Some groundwork: What is sin? I'd assert that "Missing the mark" is as good a definition as any. We can argue over where the mark is, whether placed there by God, reality, society, ourselves, etc. 

Some versions of Christianity assert that Jesus died for your sins as an atonement and that all you need to do is accept this gift of forgiveness. Some believe it's a free gift that cannot be earned but must be acknowledged and "believed". Others believe it's a universal gift that is inescapable. There are countless versions and nuances between sects. 

Let me posit that anytime we perceive that we've missed the mark (aka sinned), it's a matter of measuring the delta between the outcome we have experienced vs our expectations. 

Ultimately, isn't it up to us to accept forgiveness for missing the mark and leave that stuff behind in order to avoid it dragging us down? Whether we believe a forgiving agent is outside of us or not, we must forgive ourselves or it is pointless. 

Forgive yourself today, my friends. 

Peace.