Srpski2

Promena je proces koji se nikada neće završiti! 

I have nothing to add here because Mladen explained to you perfectly. 

Just to give you some examples:

Trka se završava. - The race is finishing " itself" (se - itself). 

Upravo sam završio svoj domaći. - I have just finished my homework.

I hope it is going to be useful for you.

If you need my help, please feel free to contact me.

Keep it up.  

Promena je proces koji se nikada neće završiti.

"završiti se" is a reflexive verb, like "zvati se", "setiti se" etc.

It would be even better to use the Present Tense when we're stating "universal truths":

Promena je proces koji se nikada ne završava.

Prijatan dan :)

Promena je proces koji se nikada neće završiti!

As is was said before, you should use the verb završiti se, the reflexive one, because there is a clear difference between reflexive and non-reflexive verbs in Serbian.

završiti     - to finish something, to end something

završiti se - to finish itself, to end itself

If you want to use Present Tense for the "universal truth", then you use a different verb alltogeather, završavati se. It's an equivalet of English "to be ending itself", because some Serbian verbs can be used with some tenses and some can't. This verb is a good example of that, because we use two different verbs in two tenses for the same meaning.

I hope I cleared some stuff up for you and I hope I can help again. Contact me if you have any questions, I'll be glad to help :)

Pozdrav!