Romans 5:12  Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:

We all share a sin nature. We are born with it. There is absolutely nothing we have done that caused it, and we all suffer because of it. How do I know? The bible tells me so.

Romans 8:20 For the creature was made subject to vanity, not willingly, but by reason of him who hath subjected the same in hope,

God told Adam don’t. If God had not told Adam don’t, sin would not exist. The secret of why God said don’t is revealed in the words of Jesus, if you love me keep my commandments. If there was no command “do not eat” Adam and Eve could have and would have become self-indulgent. They would have done anything and everything without any concern for anyone, even each other.

Love is placing the object of your affections before yourself. Without at least one measure of choice love cannot be expressed. Denial of self-interests are expressions of love. Since we were created to be loved and to love, we needed an example of how to express that love. Don’t eat was the first example.

That explains the why we have a sin nature but what is this sin nature. What does it do to us?

Genesis 3:10 And he said, I heard thy voice in the garden, and I was afraid, because I was naked; and I hid myself.

Sinning should produce three results. Note here I said should!

Put the fear of God in you.

Feel exposed.

Feel vulnerable.

I said should, but what if I sin and I don’t feel those things?