Imagine if that person did all the same things they do, but without the label of "religion" being attached.
Charity? Awesome! Habitat for Humanity is an explicitly Christian organization and does great work. In my neighborhood, the local Lutheran and Quaker churches give out free food to the poor, and they don't sneak any Lutheran or Quaker cooties into it. If you're good to others because you think God wants you to be good to others, that still really does count as being good to others.
Prayer? Okay, take "religion" off of it and they're meditating, thinking, or talking to themselves. That's good. Unless they're thinking and talking about torturing their neighbors eternally, or something creepy like that. (But even then, better to keep those fantasies to yourself than to act them out in public.) Die Gedanken sind frei — thoughts are free.
Going to worship services? Okay, they've got a weekly social event where they sing songs and listen to speeches. Sounds great, unless the songs are about "everyone outside this room is a terrible person and deserves to suffer forever" and the speeches are about hate politics. If they're about how wonderful it is to be nice to each other, or being brave and standing up against oppression, or something else that would be positive even without the label of "religion" on it, great!
Dietary rules? It's okay to have preferences, distinct cultures, cuisines, and so forth. For that matter: my family isn't Jewish, but when I was little, we ate kosher beef hot dogs, because my mom expected the rabbis would care about the meat being sanitary. (Unfortunately in retrospect, kosher slaughter is, shall we say, not clearly better than secular slaughter.)