Here's what I'd say to those banner-makers.
By never challenging or even abstaining from the assumption that it is normal and ok to force your religious views into secular law, you enabled your more numerous and powerful fundy coreligionists to assume de facto political hegemony with no counterweight but the impotent whimpers of a handful of nonbelievers. By speaking against them only with excruciating timidity and mostly, like this, after the fact, you enabled the hellfire crowd to assume the unquestioned voice of what it means to be Christian in the US - and that voice never stops screaming that it means hate and exclusion and scorn and marginalization.
So spare me the $50 QuickPrint banner empty "apology" and get off your fucking smug oh-I'm-such-a-nice-Jesus-fan asses and do two useful things for once:
1) Accept that your beliefs do not belong in our laws and speak strongly and consistently against any group that wants to enact theirs - even if, as is likely to be the case almost always in the US at least, they are fellow Christians.
2) Put your numbers and money and power where your mouth is. Your coreligionist hatemonger brethren bought their own media and started their own rich and well-connected pressure groups to more effectively preach hate and hell. Why do you fuckers hide in thousands of tiny 12 member churches and only glurge about love and tolerance to each other? Where's your 700-club? Where are your AFA and FotF? Where are your megachurches and televangelists? Where are your PR geniuses like Fischer and Graham? You pretend you are the real voice of Christianity? Then stop being so fucking shy about using it and maybe that claim would be more credible. We know who speaks for Christianity now and it sure as fucksticks isn't you lot.
Then, and only then, will your pathetic "apology" mean shit. Then, and only then, will "Christianity for all" become anything but the deadly and horrifying threat I see in those words now.