Re: Nita: I've been honestly studying Catholicism since December (with a bit of a break here and there), mostly from Catholic sources. I figure I've heard about it from non-Catholic sources for 23 years, so don't have a problem with looking at it from "the other side" (or "the horse's mouth", as Kimberly Hahn said to Scott Hahn). I've still looked at a couple non-Catholic sources here and there, but they all seem so biased (of course, the Catholic ones might have a slightly pro-Rome bias :D) now. For example, a renowned religious encyclopedia (borrowed from my father, a pastor) mentioned the lack of intellectual weight in Catholicism. I guess he forgot about Aquinas. And Augustine. ad infinitum. I tried to list out remaining holdouts I had, issues where I couldn't see any way to believe what the Church teaches. Based on my (limited, human) knowledge of Scripture and my (limited, human) knowledge of Catholicism, I couldn't come up with a single issue that I could honestly say is contrary to Scripture.
Of course, this is not the same as being at that point where I can cross the Tiber yet. Sort of somewhere between the intellectual realization that it certainly could be, that I can believe it, that it is completely defensible from Scripture and tradition (not to mention logic, for the most part) and the point where I can embrace it. Between the head and heart. But I believe the Holy Spirit is moving me towards both.
Re: Original Topic:
I suppose I should clarify my original question (though I believe it's been thoroughly answered!). I have no issue with Sunday worship vs. Saturday worship. I simply pointed to that as a common application of this passage in our area. There's one rather charismatic fellow in our town who is a sort of neo-Judaizer type.
My original question was whether or not this passage could be applied to days when Catholics are obligated to go to Mass. I'm sure if many non-Catholics I know learned about these days, they would apply this passage, making it into a "You're trying to put us under the Law" type thing.
To re-state my original question:
In Catholic doctrine, could this passage apply also to the days established by the Church? Couldn't one argue that, if all days are equal, wouldn't it be a matter of personal conviction?
To answer my original question (from what I understand based on replies):
Paul was writing to a mixed audience, telling them that, if they want to celebrate their traditional celebration days, feasts, etc, that's OK. If some don't feel like they can, then they must not (need to follow conscience). Those people with weak consciences mustn't impose that on everyone, but those with strong consciences that won't stumble shouldn't cause others to stumble.
Todd Easton, your comment is especially helpful. Many of my mindsets have shifted (surprising to me!) to a more Catholic position than Protestant. I understand the idea of matters of discipline, but I guess it just didn't come to mind.
Thanks everyone, for your replies!