My wife's mind is not enslaved when she lights the Hanukkah candles and sings the blessings that have been handed down to her through the generations.
She is simply taking part in a tradition that is important to her identity as a Jewish woman.
Religion certainly can harden hearts and enslave minds, but so can atheism.
The FFRF is taking the very worst that religion can muster and using it to paint everyone with the same bold brush strokes, a tactic perfected, ironically, by radical religious groups seeking to brand all nonbelievers as immoral devil-worshipping heathens. How easily the FFRF stoops to the same level. Pot, meet Kettle.
After some discussion in the comments, I must qualify my position on Gleeson's piece. I do think that atheists can be hard-hearted people; anyone can be. I do not agree, though, that atheism itself can "enslave" a mind. Atheism is nothing more than not believing in a god, and there are no dogmas or creeds one must subscribe to, no requirement that one throw evidence to the winds in determining how you learn about the world. A person, however, can be atheist for irrational reasons, such as simple rebellion towards or hatred of religion and religious people. Most atheists I know and have had the pleasure of working with base their atheism on a rational critique of religion's claims, but there are foolish people in any group. And if your atheism is rooted in unreason rather than reason, then yes, you can be a hard-hearted person whose mind is enslaved to anger and emotionalism, instead of being liberated by reason.