Ok, I didn't read the whole thread, so I'm taking a stab at this.... But I think what F&L may be trying to say (correct me if I'm way off, F&L) is that many on the left, namely the ones who don't lean to the libertarian side, are a lot like the religious right who want to use the force of law to push through a certain agenda.
I don't think it was necessary to call liberalism or atheism a "religion" - maybe what he meant was that some are almost "religious" (in a different sense of the word, more like zealous or dogmatic) when it comes to their worldview, and using the law to change society.
Just wanted to try to get somewhere here, because all I can see is a lot of bickering.
Therefore we do not lose heart. Even though our outward man is perishing, yet the inward man is being renewed day by day. For our light affliction, which is but for a moment, is working for us a far more exceeding and eternal weight of glory, while we do not look at the things which are seen, but at the things which are not seen. For the things which are seen are temporary, but the things which are not seen are eternal.
2 CORINTHIANS 4:16-18