Is it possible to not sin at all?

As imperfect humans it is impossible for us not to sin.We inherited sin from Adam-Romans 5:12.We can receive forgiveness fo our sins by exercising faith in Jesus ransom sacrifice-John 3:16.Learn more at jw.org.

If so, then you can 'throw the first stone'
Jesus did not sin.

WHY DID JESUS DIE? Unlike us, Jesus was perfect.  So he did not need to die for his sins- he never committed any. Instead, Jesus died for the sins of others. God expressed extraordinary love for mankind by sending his Son to die for us. Jesus also showed love for us by obeying his and giving his life for our sin. Read John 3:16;  Romans 5:18,19.  WHAT IS JESUS DOING NOW? When on earth, Jesus cured the sick, raised the dead, and rescued people in peril. He thereby demonstrated what he will do in the future for all obedient mankind. ( Matthew 15:30,31; John 5:28) after Jesus died, God restored him to life as a spirit person. ( 1 Peter 3:18) Jesus then waited at God's right hand until Jehovah gave him power to rule as King over all the earth.(Hebrews 10:12, 13) Now Jesus is ruling as King in Heaven, and his followers are announcing that good news worldwide. Read Daniel 7;13,14; Matthew 24:14. Soon, Jesus will use his power as King to bring an end to all suffering and to those who cause it. All who exercise faith in Jesus by obeying him will enjoy life in a paradise on earth. Read Psalm 37;9-11. For mor information JW.ORG

No, because human beings are not perfect. God alone is perfect, and the closer we come to Him, the more we are able to resist sin. But we will never become perfect.

Not possible. Even your very thoughts can convict you. Jesus brought this out in Mt. chapter 5.  People are born sinful beings. You are sinful, not because you sin. You sin because you are sinful, by nature.

It is a contradiction in terms to claim that a person may not sin at all, yet nobody is perfect. Only a perfect person would not sin ever! Only Jesus never sinned at all, because He was perfect! It is equally illogical to admit that everyone makes mistakes but then to claim that mistakes are not the same as sin. Oh yes they are, when those mistakes are an offense against God! Sin is anything that goes against God. "All that is not of faith is sin" the Bible warns us - Romans 14:23.

The Bible also warns that even when we are doing the right thing - something good - our motives may be sinful and displeasing to God. "All our righteous acts are as filthy rags" God's covenant people had to admit - Isaiah 64:6. Those who are genuinely humble before the holy and righteous God will agree with His verdict on us: "There is no-one righteous, not even one" - Isaiah 64:7 quoted in Romans 3:10. But our sins can be wiped away because of the sinless sacrifice of Christ - if we repentantly put faith in what He did to deal with our sin nature. Then the Holy Spirit will lift us up to become more and more Christ-like. When we sin, as Christians, we find forgiveness in confessing in prayer to God and seeking fresh pardon. Read all of the apostle John's first epistle to learn about that.

Ecclesiastes 7:20 says: “For there is no righteous man on earth who always does good and never sins.”

It is quite difficult to suppress something that is innate to your nature. It's like refraining yourself from breathing, which is hard because eventually you will yield to the pressure and release your lungs. 

No, so thankfully God doesnt demand perfection. Just a life committed to God whereby we grow more in his image every day for the rest of our lives.

Christ is the image of God, and Christian means Christlike. 

I dun really know .. hehe.
However, the bible say to repent when we sin .. God forgives.
We r not perfect, can never be. So get real.
We do sin now n then BUT we must quickly catch ourselves n repent b4 God's judgment comes.
Thats the best i know.
I wish i could stop sinning for good, permanently but damn .. the devil knows just how to make us fall.
The bible says .. be sober. 
So, i try my best n i never gv up trying. God help me.

Maybe, if one is in vegetable state on life support whole their life