Wolfgang , people can't be certain about these things - that's why we commit our thoughts to paper and thereby we continue the search . We're allowed to dismiss or reject other peoples opinions just as we can accept that they possibly have merit. We share and explore the arguments and the notions, but the Subject doesn't lend itself to accepting or rejecting FACTS - because with religion, the facts which puportedly exist are more times than enough - rejected by other religions or members of a similar religion.
For example is the Eucharist THE body of Christ or just a symbolic gesture. How many people / Organised Reigions does this foundation stone - divide ???
Read it all - you don't have to accept one single word - and what you read may even strengthen your religious convictions.
Little Hawk tells us you are a Scientist , I'm an Engineer and maybe the two of us suffer from the same problem in that we see every situation is governed by Engineering Rules and Scientific Principles which are enough for us determine definite answers.
Unfortunately this Subject can never povide us with a modicum of certainty (based on facts), however one's Credo and Faith have been challenged but hopefully they still remain intact to the comfort of the holder.
That they get tested from time to time (by whatever means) is no bad thing for a healthy mind.