From what I understand, every human that has ever lived is "born into sin", which means we all carry a "sin nature". Saul says:
"For all have sinned, and come short of the glory of God" Romans 3:23
This means even little cute babies. If I'm not mistaken, most churches believe life begins at conception (which I have no problem with), so that means as soon as a baby is conceived, they are sinners before God.
Just to clarify, I'm not looking for answers from those that hold to the "age of accountability". If anyone believes in this, please leave a comment and I'll ask a separate question.
My question is...
What is the first sin an infant (or fetus) commits?
I've considered that this may be too broad of a question, but since infants can only do about 10 things (lay down, babble, drink milk, poop, etc), it shouldn't be hard to pinpoint that one thing that causes the infant to be a sinner deserving to have it's flesh burned forever and ever in agony.