They don't overtly claim it is the ONLY way to think, but I am suspicious they are doing it covertly. I just asked a question about this on the homosexual thread. They insist the Messenger has connection with God, and the writings are absolute. Well if that is what they believe then everyone else is dead wrong. They might not come out and say we are wrong, but they certainly imply it as they claim their Messenger MUST be authentic, and the texts ABSOLUTELY from God. They are so adamant about these texts being absolute that they can't even remove the homophobic parts. With all the arguments against their immoral text and belief they stand firm. That they continue to defend their beliefs, often with distractions and deflection, indicates they are firm in their belief and defiant against criticism.No. They tell people what they believe, as do I, but they don't typically tell people that is the only way to think.
A smart thing to do, as some Bahai have done, is to bow out of the uncomfortable discussions. If they really believe the texts are from God and accept that gays are to be condemned, then they should keep that private. It they decide to keep up a defense for an immoral view then they bring on suffering for themselves, and taint the image of their religion that much more. An even smarter move would for the Bahai (assuming they aren't bigots) to offer prayers to God to change this law. That would save face, and suggest there is an oen dialog with God to adjust the ban on gays.