Then apparently your experience, reason, and study of religion has been completely blind to one of the primary consequences of religions and their antagonisms; that is, it has been a primary source of division and war among men; NOT unity. I have no idea where you got that ridiculous pipe dream.

Your analogy is completely incompatible to comparison to differences in religion. First of all, the 'guys' and their descriptions of the couch are expressions of very broad relative opinion. The main posit behind the world's religion, being faith, expresses a truth value (albeit one without evidence); anything contradicting the set truth value is incompatible with that religion (e.g. Jesus is the savior and son of God and the only way one can be saved is through Jesus [Christianity] vs. Jesus is an irrelevant figure who (if he even existed) preached about a God and about permanent existence that isn't there, thereby perpetuating an ignorance of inherent existence and separating individuals from the universal 'spirit' [many eastern religions, etc.]).

Guy 1 doesn't kill guy 3 because it is a mere opinion. However, if guy 1's religion told him the undebatable 'truth' that it is an abomination to use the couch to 'nail the babysitter', then we have an undeniable contradiction and maybe guy 1 will actually kill guy 3; you know, just like some Muslims in the middle east are killing 'infidels' for not accepting Allah and Muhammad and just like virtually every war and inquisition conducted during the Middle Ages.

Likewise they're talking about the same subject (couch). Unlike many differences in religion.

The essence of religion has always been lies, as Hev points out (I wouldn't personally say lies as the teachers of religion believe in the same delusion as their followers; I would personally say the essence of religion has been delusion and a false sense of comfort [opium of the masses]); and it's distinct feature is division not unity. It makes humanity focus on each others' differences as opposed to their commonhood.