We do theology by the behavior of some or scripture?
Yes, we try but often fail.
I stated in Christ is no sin and took pain to post the commandments kept. Apart from those commands I decline to go down that rabbit hole.
Of course you don't want to go down that "rabbit hole"
Jesus gave us commandments to "enhance" our walk with Him.
Do we break those commandments? Of course we do. despite being saved we still have a sin nature which won't be fully removed until our sanctification is fully completed.
The saints are defined as those who hold to the testmony of Jesus and keep God commands.
A good tree doesn't bear bad fruit.
True...but of all the apples on a tree not all the apples are selected for the apple pie.
A christain as you state that sins from time to time if they remain in Christ they have no sin. In Him is no sin.
Yes, Jesus has no sin. On the cross Jesus became our sin.
Whoever has the Son has life; whoever does not have God’s Son does not have life.
Because one sins...it doesn't mean they don't have eternal life.
Through the power of Christ Jesus, repentance, we can sin less. The bible tells us God always gives us a way out of sin and we often choose to reject the way out. Sometimes out of ignorance while some times choosing the false instant gratification of sin.
All Christians sin. All. To that I might add if after your confession in Christ you still sin they way you use to sin you might want to re-look at your confession and determine if you really believed and are saved.
Thankfully Jesus died on the cross and ALL of our sins, past, present and future have been imputed to Christ Jesus.
Because of that in a sense "we don't sin"...or have those sins presented to the Lord as they were nailed to the cross and washed away (forgiven) by the blood of Christ Jesus.