In this thread, the comparison is about Jesus and Buddha...Bahaiullah is irrelevant. Since neither wrote anything whatsoever, authenticity can only be made plausible through historical critical analysis, but never be definitively established or refuted.
Well maybe to your view it is irrelevant, to a Baha'i view Baha'u'llah has confirmed they are from the same source and that we will find common themes.
The key is one has to want to and be motivated to, look for what binds them.
In that critical analysis of Buddha and Christ, Baha'u'llah has also given another key thought,
All good is from God, the source of both Buddha and Christ and all else is from our own selves.
I am willing to suggest both Buddha and Christ would have offered the same advice.
Regards Tony