Are we sinners because we sin or do we sin because we're sinners?

Response to comment [from a Christian]:  "You are making a simple subject confusing."

Did Jesus have a sin nature?  Was his nature different than our ours? Ps 51:5.

"...[B]eing human does not make one a sinner; being a dog does not make one a sinner..."

The nature of a dog is to bark and they do bark.  The nature of a cat is to meow and they do meow.  The nature of man in Adam is to sin and they do sin (Ge 3:6,7; Ro 5:12).

If all men are conceived and born in sin (Ge 5:3; Job 15:14; 25:4; Ps 51:5), shaped in sin (Ps 51:5), under sin (Ga 3:22); and no man is without sin (1 Ki 8:46; Ec 7:20), how is Jesus different?  2 Co 5:21; Heb 4:15; 7:26; 1 Jn 3:5  Did he have sin genetically or physically? 

"Jesus was tempted like we are, yet without sin. Sin is volitional/moral, not genetic/metaphysical."

Who is Jesus' father?  Could he have sinned?  

"Jesus had a human and divine nature."

Did he make a voluntary choice to leave heaven and become a man?  Did he take upon himself the weakness of humanity while never losing his divinity?  Was his divinity veiled with human flesh?

Response to comment [from other]:  "...[I]f Jesus was just a man, then it'd be tough for Jesus not to have a sin nature."

If he was not sinless (2 Co 5:21; Heb 4:15; 7:26; 1 Jo 3:5), he cannot save us.  He would have died for his own sin.  

Response to comment [from a Christian]:  "Sin is not a thing that can be passed in sperm, blood, etc. (transducian theories)..."

Can a sin nature be passed from men born in Adam?  Ge 5:3; Job 15:14; 25:4; Ps 51:5, Ga 3:22, 1 Ki 8:46; Ec 7:20.

[Can a sin nature be passed from men born in Adam? Ge 5:3; Job 15:14; 25:4; Ps 51:5, Ga 3:22, 1 Ki 8:46; Ec 7:20] "How can murder be passed on genetically?"

If a sin nature cannot be passed on from men born in Adam, why did Cain murder his brother? Ge 4:8.  

"How can a zygote be a sinner when they lack moral/mental capacity."

Ask David how he got a fallen, sinful disposition since conception (Ps 51:5).

"In your view, babies should go to hell."

If God chooses to save babies before the age of accountability, he is merciful (Rom. 2:12–16). 

"Lucifer and Adam sinned without a sin nature."

Satan was a murderer from the beginning (Jn 8:44).  Are murderers fallen?  

Sin is transgression of the law.  Did Adam break a simple rule?  1 Jn 3:4.  Why did Adam notice his nakedness and try to cover it?  Ge 3:7, Jn 16:8,9.   

"Why do some atheists not murder/adulterate while some Christians do?"

Are Christians sinless or do they sin less? Ro 7:19-20.

"If God arbitrarily shows mercy to some, He could do it for all."

God does show mercy to all (Ex 34:6,7; Ps 62:12; Ne 9:17; Jon 4:2,10,11; 2 Co 1:3).  What's your point?

"Universalism is heretical, unbiblical."

Strawman.

See:

Is universalism / universal salvation Biblical? If Jesus died for the sins of the entire world, does that mean that everyone in the world is saved?

We were discussing sin nature and how Jesus was/is different.

I think we agree that if we were able to live a perfect, sinless life, we'd go to heaven. However, that does not happen because of our sin nature. Jesus lived the perfect life that neither you nor I could live. He died for our sin not his own.

Are we sinners because we sin or do we sin because we're sinners?