This thread was started by a Muslim who was highlighting a festival, and wished all well - whether Muslims or not. I wouldn't call that 'bringing it'.
In fact I had no idea about the Eid festival so asked about it's origins and significance, so he kindly bothered himself to post the background of it, so I could understand.
It was only when there were some barbed jibes thrown that it turned into him somehow having to justify his faith.
Let me ask you a question, if I posted a thread wishing all and sundry Happy Christmas, would it end up with me having to justify my Christianity within 3 pages?
I think not.
That may well be how the thread started, but that isn't what I was asking about, and threads rarely stay on teh topic of the OP. If anything, this is odd in that it is on topic.
Threads on Christmas regularly get into questions about its origins and relevance, often pointing out that, like easter, it's an adoption of a pre-existing festival and questioning the whole concept..
My main point is that many strongly religious people have dismissed other religions, in the self and same way atheists dismiss all. In fact, it's probable that atheists have looked more closely at various religions before making their choice. They're only one god apart.
They've either considered it, and dismissed it, in which case I'm interested in what grounds they dismissed it on, or they haven't considered it, in which case I'd argue that their faith is by definition poorly informed.
People can have faith in islam, reptilian shape shifters ruling the earth, santa, or Macclesfield becoming European Champions. They all fall into the same category.
There's nothing to fear in discussing that.