If the first amendment is to have any meaning, then religious speech and expression cannot be proscribed any differently than secular speech. So, just like I can't go into a crowded movie theatre and yell "FIRE!!", neither can I go and try to incite people to burn down abortion clinics or stone the local prostitutes (w/rocks, not weed
) w/o there being legal repercussions. On the other hand, like in SW's example, if someone decides they want to bend my ear about their religious beliefs, I merely need to excuse myself from that person's presence or explain that I'm really not interested. Or, if I want to really be a dick, tell em to F off. Of course a very passive-aggressive way would be to completely shut them out by using an ipod or walkman.
But as I stated before, there are no obvious prohibitions in this country about ridiculing religious belief. Forums abound for people who detest or otherwise view w/contempt--amused or otherwise--religious beliefs. Also, people of religious faiths, like their secular counterparts, have as much right to try to influence the laws of their nation. As the US is still more or less a democratic republic, EVERYONE who is eligible (>18) has a right to vote to see their view represented in the laws of the country. BTW that doesn't mean that they have the right to make their will law, just to vote for people they believe will represent their particular point of view and encode it in law.