Q. Did Adam and Eve have sin nature in them? What made them ignore God’s warning and listen to Satan instead?
A. Adam and Eve were created with agency, which is the freedom to make choices for themselves, but not a sin nature. Satan took advantage of that freedom. He persuaded them to disobey God’s direct command and eat from the tree of the knowledge of good and evil. Since then all humans have had a sin nature, a predisposition toward sin. The sin nature is not something that makes it possible for us to sin. It’s something that makes it impossible for us not to.
1 John 1:8 says, If we claim to be without sin, we deceive ourselves and the truth is not in us. But here’s the good news. If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. (1 John 1:9)