1 John 2:1
My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous:
Of course we are not to sin but, it is obvious to Jesus that he understands that we are not capable of not sining. Not that we want to sin but, we are not perfect like he is and we are not capable of no sin.
Jesus acknowledges this to us by saying: " And if any man sin"!
Then he follows up by saying that the Holy Spirit speaks on our behalf when we do mess up.
RJ, it is quite interesting to see the way you think about scripture. By this verse you stated that it is obvious that Jesus understands we are not capable of not sinning.
First of all the quoted verse above is from the KJV and I love the KJV but they didn't always bring out the fullness of the text in their interpretations. Youngs literal translation captures the use of the subjunctives which are necessary if we are going to understand that the 'if' used here is a third class condition in Greek that denotes a hypothetical situation and not something absolutely certain.
My little children, these things I write to you, that ye may not sin: and if any one may sin, an advocate we have with the Father, Jesus Christ, a righteous one,
These are not absolutes either way. So to say Jesus understands that we are not capable of not sinning based upon this verse would be in error. If Jesus were trying to acknowledge our inablility to stay free from sin he could have very well said "So when you sin" but he did not.