Is this a remake?

Beginning is a "remake" of DOMINION - ONLY in the bizarre sense that Schrader handed the first cut of his prequel Dominion to Morgan Creek - who said it was "too cerebral", "not scary enough", and dropped Schrader and his film. Thus Dominion is the first, original filmed and INTENDED prequel.

Morgan Creek, still wanting to get SOME kind of prequel version to the screen, brought in Renny Harlin to "repair" the perceived flaws in Schrader's film.

They are two different films, but with the oddity of duplicating filming locations; having Merrin/Stellan Skarsgard being assisted by a young priest played by a different actor for each film; having a "love interest" for Merrin played by a different actress for each film; having a young person as the possession victim; presenting a background of colonialism/racism.

So:

Schrader directs the original sequel, Dominion.
Morgan Creek rejects Dominion, fires Schrader, hires Harlin.
MC accepts Harlin's version, puts it into the theaters.
Finally, with very little time allowed for sfx and other improvements, Schrader's Dominion is given a short theatrical run, then channeled into DVD format.

Just FYI: Exorcist author William Peter Blatty called Dominion "an elegant film".