Do you think we will ever become one world (similar to Star Trek)?

Maybe eventually, but most likely not imo. It would take massive death on a global scale for people to come together. I'm not even sure they would then as people would be all for themselves or their local faction rather than coming together globally.

Ideally this is what needs to be done, but in actuality it probably will remain problematic for a long time.

Not just like a "one world" amalgamation of countries/nations and such, but us all being on the same page as a species for moving forward/development/etc. This is much easier to picture in theory, but extremely difficult in practice it would seem. There always seems to be some people who more strongly lean/have an affinity for their "group" or you know what I mean....

This is the issue with being "your own person" vs. being "someone of a certain background/culture/identity." Not saying acknowledging and being comfortable with one's heritage or such is bad, but in doing so you immediately create a separation or difference with you and others not of the same background. While people can do this and identify strongly with each of their own backgrounds/cultures/etc. while still getting along with others (who presumably might be doing the same themselves), what happens is this always seems to become some sort of identity crisis for some people. Some people want to be ignorant, but then also want to approach things like they aren't.

People want to say, "We're all the same," while contradicting this a bit by having a powerful affinity to their heritage/cultures/etc. and thus possibly pushing away others due to this. There are also far too many people who define themselves too strongly with non-pliable associations like religion, politic leaning, family cultures/beliefs/actions and so on. I don't have a problem when people are different, but overall this seems to always create issues one way or another when you look at the current social mishaps/issues seen today.

Not for many centuries, although there are globalists out there attempting to do it the evil way and play the long game.

No.