To whom it may concern,
If you have an opinion state -- In my opinion.
If you are not absolutely sure about a detail you can say -- it appears to me, apparently, it seems to me, etc.
These are important distinctions.
Specifically qualifying what you say in this way makes it very difficult, even for a litigious group, to have any meaningful basis to make a claim regarding defamation.
Forum: "Cults," Sects, and "New Religious Movements"