I believe Jesus saying "go and sin no more" was just a figure of speech in which he was trying to get her to stop sinning but obviously he knows it's impossible for a human to be perfect.
No, it means exactly what it says, because Jesus further said in Matthew 5:48,
"Be ye therefore perfect, even as your Father which is in heaven IS perfect."
That is therefore the goal that God wants each of us to have. There were no if's, and's or but's added... and Jesus knew exactly who he was talking to! That is therefore clearly what God wants for us. But He doesn't just say to us, go and do this, go and do that, and then leaves us alone. Because He is there with us, even if we may not realise it. He is always there with us and only He has the the power to save us (He is always with us, but we are not always with Him - so if we sin then the problem lies with us).
Jesus further said, that we have to become like children in order to enter The Kingdom. What do children do? They
trust. You tell a little child something is possible, and they will believe you, even if they can't yet see how, because they will put their whole and full trust you. In that situation, you may know from experience that what the child can't understand yet as being possible for them, is indeed going to be possible. We therefore have to trust God in the same way if we want to succeed, because He knows what we do not know.
It's important therefore to also learn to have a good attitude and not fall into defeatist thinking (all of which is lies, coming from satan).
If God says something is possible, shall any man then be able to say otherwise? No. As Paul said, "Let God be true, and every man be a liar."
Of course, I believe we should try our utmost best to try not to sin but we're humans and we fall from time to time no matter how perfect we might feel we are or are you saying that you never sin?
Understood. No, was not saying that or claiming to be perfect, but saying that it is definitely possible to do what God asks, because with Him all things are possible, and that we therefore have to be striving:
Philippians
3:8 Yea doubtless, and I count all things [but] loss for the excellency of the Knowledge of Christ Jesus my Lord: for whom I have suffered the loss of all things, and do count them [but] dung, that I may win Christ,
3:9 And be found in him, not having mine own righteousness, which is of The Law, but that which is through the faith of Christ, the righteousness which is of God by faith:
3:10 That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;
3:11 If by any means I might attain unto the resurrection of the "dead".
3:12 Not as though I had already attained, either were already perfect:
but I follow after, if that I may apprehend that for which also I am apprehended by Christ Jesus.
3:13 Brethren, I count not myself to have apprehended: but [this] one thing [I do], forgetting those things which are behind, and reaching forth unto those things which are before,
3:14 I press toward the mark for the prize of the high calling of God in Christ Jesus.
3:15 Let us therefore, as many as [want to] be perfect,
be thus minded: and if in any thing ye be otherwise minded, God shall reveal even this unto you.
Would share with you something I was taught, just in case interested... that instead of saying you "try", a much better word to use is you "strive".
Muslims for instance talk about Jihad, which I believe means to strive, to struggle - it's the struggle against one's "self" and the goal is to eventually defeat and then overcome it. That is why we are here, that is actually the point of this life. That, to work on defeating the "self" (which is only possible with God's help), is the first and most important jihad. If we strive and don't ever give up, then it means the goal is to succeed and that will then be the eventual outcome, God Willing. But, if we only "try"... then we might as well give up before we start.
How do we know what sin is? Sin is defined as transgression of The Law (1 John 3:4), so it is important that we read and study God's Law in the Scriptures in order to learn what sin is. God's Law shows us the goalposts and the difference between right and wrong. And it is not impossible to learn to keep God's Laws, because God says so and He also teaches us to know His Laws and His Ways, from within (so we will know, if we listen).
Only God can teach each person how to be perfect, in
His eyes, because only He knows what we are capable of and also what exactly it is that He wants us to learn.
Fasting is a very effective method for overcoming the "self" (fast), because fasting is the starving out of "self". Jesus demonstrated and taught fasting to his followers
by Example, by Fasting 40+ days on water only, before beginning his ministry. The Qur'an also tells Muslims to fast during Ramadan, as it teaches "self" restraint.
So, it a tool for growth that we can and should be using, likewise.
Even short fasts can be very helpful, both for the mind and the body. There are many incredible health benefits to fasting, as the body begins to rapidly expel toxins and cleanse itself out of accumulated toxins and diseased tissue during the process. Many people have been able to completely heal themselves of even serious illnesses like cancers, etc. through fasting.
But, that is just a side effect, as the real and true benefits of fasting are of a spiritual nature.