Can any Muslim look down upon or give bad character judgement about other Muslims/Non-Muslims

Sometimes whenever we see a bad person doing bad things, we make up our mind that this person is definitely going to hell.

Jundub Radi allaho anho reported that Prophet Muahammad (may peace be upon him) stated that a person said: Allah would not forgive such and such (person). Thereupon Allah the Exalted and Glorious, said: Who is he who adjures about Me that I would not grant pardon to so and so; I have granted pardon to so and so and blotted out his deeds (who took an oath that I would not grant pardon to him).(Sahih-Muslim- 6681)

We should be cautious in giving our final judgment towards any person. We cannot even say to Non-muslims that they will all go to hell because we are are very limited beings in our knowledge and only Allah knows takdeer( predestination) of everyone, so He knows who will repent later or come to the right path before death.

Thank you for your time. If you are confused about specific issue or want to talk about anything related to Islam, you can mention them in comments and i'll try to address them in upcoming posts.