Q:

Is it Islamic belief "Hate the sin, not the sinner"?

or is there something else that is opposite or similar to it...
From all the teachings i have received the rule I'd say is Islamic is do what's the best. Basically people change so labelling someone as sinner may make us overlook his/her good parts and overlook their change if it occurs. 
Please provide hadiths/Quran if possible

A:

“Hate the sin, not the sinner” is only partly correct in Islam. Only a sinner with sins wholly occupying his heart making his heart dark lacking any light spot survived in it is one we should hate and even curse against them, though, if we can identify them correctly. About any other sinner no we cannot hate himself, but we must hate the sin, and the majority of the sinners belong to this latter group. The former group are those who would be left in the hell eternally, the rest will be survived from the hell and let enter the heaven after centuries and maybe millenniums or more of being tortured in the hell.
Those with completely dark hearts will never find the opportunity to repent in Dunya (world), they are Taqut (طاغوت: or leaders inviting to the Fire: أَئِمَّةً يَدْعُونَ إِلَى النَّارِ‌, Al-Qasas,41) against which Allah has ordered us to be Kafir about them. The others we should always have hope that they may repent, and we should help them so by enjoying them to what is right and banning them from what s wrong.

اللَّـهُ وَلِيُّ الَّذِينَ آمَنُوا يُخْرِ‌جُهُم مِّنَ الظُّلُمَاتِ
  إِلَى النُّورِ‌ ۖ وَالَّذِينَ كَفَرُ‌وا أَوْلِيَاؤُهُمُ الطَّاغُوتُ
  يُخْرِ‌جُونَهُم مِّنَ النُّورِ‌ إِلَى الظُّلُمَاتِ ۗ أُولَـٰئِكَ
  أَصْحَابُ النَّارِ‌ ۖ هُمْ فِيهَا خَالِدُونَ
Allah is the ally of those who believe. He brings them out from
  darknesses into the light. And those who disbelieve - their allies are
  Taghut. They take them out of the light into darknesses. Those are the
  companions of the Fire; they will abide eternally therein.
  [Al-Baqareh, 257]

Godspeed

