A myth that I continue to see tossed around on the Huffington Post is the claim that Israel's claim to the land is solely based on either (a) the fact that Jews lived there thousands of years ago or (b) that the Jews have a religious claim based on their beliefs. It's usually the latter, and after making it the talkbacker will sneer at the Jews for actually believing in such archaic tomfoolery, let alone building a country out of it. Here is one example, though there are plenty should you choose to go and find them:
Most Israelis (even most settlers) are not very religious and more than a few of them are secular. This is somewhat counterbalanced by the perception that the minority that are very religious are also pretty fanatical about it. Even most of the settlers are not there because they believe that the West Bank is the land promised to them by God, etc etc. They are there because of cheaper housing, about as secular a motivation as you can get.
As for Israel's existence, there are innumerable laws and documents recognizing that Israel has every right to exist on that land. They include Balfour, UN recognition, and so forth. This is far more than most countries have, and it is even more than the Palestinians have, when you want to put it that way. Therefore it seems to me that this whole religious argument is just another strawman: It's easy to knock down someone else's unheld religious beliefs, so better just pretend that they hold them and make fun of them accordingly. It's much harder for an HPer to argue with the UN and the international community than with a religious person, especially in our secular age. Really, it just shows more anti-Zionist ignorance not only about Zionism itself, but about Israel and it's people. Can't say I am surprised, though.