The messiah series shows the idea of Dajjal...and the realities revolving around it. Are Muslims supposed to stay away from such show or can they watch it gain some knowledge?
I've watched an episode.
I don't think this series is showing the idea of Dajjal at all. In Islam Dajjal is One-eyed man. Also, 70 thousands of Jewish from Isfahan will follow him in the beginning.
For me, I don't think they mean Dajjal. I think they mean Jesus. He also messiah but the true messiah not the Liar one (Dajjal). Even though, the text written is bad and some quotations from Quran are used in wrong way.
There are many resources to look if you want to gain knowledge about messiah Dajjal or the messiah Jesus peace be upon him but not this resource.
Before I try answering the question I want to highlight the folllowing:
If I understood the question correctly, it is regarding if you are allowed to watch the mentioned series.
The second question "but can I do it if I gain some knowledge from it?" Basically, the second question is only relevant if the answer to your main question is "no". In that case it might be better to ask another more general question like; "Am I allowed to do/watch something haram if my intent is to gain knowledge in order to perform better spiritually?" This is not in scope of this answer.
- The answer is not regarding if you should watch movies or not, or do something "better" with your time.
- I won't mention why you shouldn't watch the series.
Basically, watching this series goes along the ruling watching any other movie or series. See for instance this and this question. Also as a note on one of the answers saying you shouldn't watch it if it goes against Islam: Is the movie trying to convince you about believing on something that goes against Islam or not? If not, then it's hard to call it haram. In that sense you can't even watch the news.
I haven't watched the series, but as I said, the ruling goes a long wacthing any other series. And maybe there could be positive to watch it in order to get a sense of how other people interpretate the islamic view of this topic. This could then be used to remove misconceptions, or maybe open up a new perspective for you (which might be good if its positive interpretation).
As an example of what I mean with perspectives, @Mohammad Aldawsari states in his question the following:
I don't think this series is showing the idea of Dajjal at all. In Islam Dajjal is One-eyed man
This could be the case, but after reading about the series it is clear that the producer wants to leave some room of speculations if this is the dajjal or messiah they are picturing in the series.
But certiantly, what he mentions in his answer comes from an approved opionen from an islamic standpoint, for instance it is mentioned in several hadiths that he is oned eyes (see this).
The following will be opinion based and hypothetical. If we look back on the jews, we will notice that they had some kind of reasons of not following Jesus, either religous convictions, or maybe pride. The same thing for the Christians and Jews in the Prophets Muhammads (saw) time. So the possibility that muslims in the future might not think that the dajjal is dajjal might be because of some religous convictions, and therefore maybe follow him.
For instance, reading the hadith saying it will be written "Kafir" between dajjals eyes. What if that doesn't literally mean that it will be written between his eyes? What if it means that a "true" muslim will know he is the dajjal? The same question goes to the hadith saying he will be blind on his right eye. What if he really isn't literally blind on his right eye? But it might mean something else? (See for instance meaning of right and left in Arabic)
So, if the dajjal comes with something that somehow goes against a convication how you perceive him, and the series might help you get perspectives of an interpretation of how he might be, then maybe that is good, to help you get perspectives which will make you cleaver enough to avoid him if he appears in your path.