Avirah,
Sinas chinam is looking how each of us is different and accentuating it
So Lubavitchers believe their rebbe is moshiach and can come from the dead, so what? It isn’t an aveirah (maybe a shtus) and they won’t listen to you and you won’t listen to them
You’ll think they’re crazy and they’ll think you’re crazy
I don’t see a point to multiple “rebbe being moshiach” threads and why now?