We searched for this specific congregation by name, together with Korosiot, Seretut and Kenya, and found no page, directory entry, map listing or news item for a Maranatha Faith Assemblies branch at Korosiot or Seretut. The parent denomination is clearly real and well documented: Maranatha Faith Assemblies (MFA), first known as Maranatha Mission, began at Komotobo in 1967 under Swedish missionary Bengt Sundh, with its headquarters moved to Migori in 1988, and it is listed among the member churches of the National Council of Churches of Kenya (Wikipedia), with a published constitution on mfakenya.com. Many MFA branches run their own Facebook pages, for example in Migori, Nairobi (Kabiria and Siranga) and Rongo (Facebook), but no equivalent page exists for Korosiot. The findings are summarized here for space; the full research was weighed in the review.
Our conclusion: Maranatha Faith Assemblies is a well documented Kenyan denomination that began at Komotobo in 1967, has its headquarters in Migori and is a member church of the National Council of Churches of Kenya, so a local branch named Korosiot near Seretut is entirely plausible. Our own web search found no page, directory listing or news item for this particular branch, which is normal for a small rural congregation, and it also found no complaints or warni
No further action is needed. This report is refreshed whenever the church is reviewed again.