The story of Doubting Thomas is told, not so that we shall admire Thomas, but so that we can admire the other apostles in comparison. Thomas demanded evidence. Nothing is more lethal for certain kinds of meme than a tendency to look for evidence. The other apostles, whose faith was so strong that they did not need evidence, are held up to us as worthy of imitation. Doubting Thomas, the only apostle with more than two brain cells.
Blind faith can justify anything.
If a man believes in a different god, or even if he uses a different ritual for worshipping the same god, blind faith can decree that he should die - on the cross, at the stake, skewered on a Crusader's sword, shot in a Beirut street, or blown up in a bar in Belfast. Memes for blind faith have their own ruthless ways of propagating themselves. Intellect requires rational reason, logic and intelligence, it requires facts, evidence and proof. Faith is irrational, illogical and just plain stupid, it does not need facts, evidence or proof.