My question is how did sin come to be? I mean Satan surely sinned before man, because he existed first. So apparently it isn’t an exclusive human failing. So how and who created it?
Ezekiel 28:15-17 tells us Satan was creation’s first sinner, and his sin was pride. Isaiah 14:12-14 says this pride led him to believe he could become like God.
Both angels and mankind are created with an ability called agency, also known as the power of choice. When Satan enticed Adam and Eve they could have chosen to refuse, but thinking they were doing something good, even though they were disobeying God, they sinned (Genesis 3:5-6). In James 1:14 we’re told that we are tempted when by our own evil desire we allow ourselves to be dragged away and enticed. Satan was able to entice Adam and Eve because they had a desire to be like God, too.