Then out of curiosity, why do Christians go to church on Sundays? I genuinely have never understood what led up to the day switch - I was born and raised Jewish.

First, Christians do all sorts of things for the wrong reasons, its best to clear that first before trying to explain their actions.

Second, Going to church on Sunday and believing Sunday to be a Sabbath day are two totally different things.

In fact, keeping Sabbaths is not a Christian thing to do at all. Christians do it, but that's because they think they are (really, really want to be) Jews. Tons of the crazy stuff Christians do are because they try to adopt little pieces of the Jewish economy (10 commandments, feast days, sabbaths, etc, etc,).

I don't know when/why Sunday became the de facto day for Christian church-going, but I can answer for myself, that I attend church on Sundays because it is the most convenient day (where I live) to do so. I don't regard it higher than any other day of the week (ok, maybe Monday ;).

Sunday is the day on which Christ rose from the dead. See Matthew 28 (http://www.gnpcb.org/esv/search/?q=Matthew+28&src=esv.or...) Christians meet on Sunday to celebrate the resurrection of Jesus. At least that is my understanding.

Catholics meet on Sunday to give God his due, as he demanded in the Ten Commandments. Jesus is God, and is an intrinsic part of that ceremony. I'm not sure Jesus rising from the dead is what makes Sunday the issue.

Catholics are explicitly, overtly allowed to work on Sunday. It is, however, a venal sin to work on Sunday (a) at the expense of worship and reverence (in other words, don't skip Mass) and (b) when you had a reasonable option not to. Five generations of American Catholic men appear to have established the convention that Sunday afternoon football incurs minimal expense to revering Jesus.

Protestants would agree on the work thing. After all we have pastors don't we? I am really interested to hear an expansion of what you mean by "give God his due, as he demanded in the Ten Commandments." I am not sure which you are referring to, but that is probably my own ignorance of such things. Also we protestants like Sunday football too. Not me personally, but that comes from not growing up in the US. :)

Basically, the Sabbath was moved for marketing purposes. The Council of Laodicea in 364 ordered all religious festivals to Sunday, not Saturday. There were a few reasons for this. One, Rome was mostly a pagan country, and most pagan religions reserved Sunday as a religious holiday. So the change would have helped convert pagans, and keep Christians in the church. Two, it differentiated the Christians from the Jews, and the Jews were being persecuted in Rome them. And the Roman emperor Constantine declared Sunday to be a day of rest in 321.

Most of the biblical emphasis a Sunday sabbath comes from the fact that Easter was celebrated on Sunday, and a few verses saying that religious holiday observance didn't matter.Some Catholic Catechisms mentions that there is no biblical support for a sabbath on Sunday, and justify it by saying that the church has the authority to change religious holidays. I'm not sure if this is atypical compared to most catechisms, I am not very familiar with Catholic theology.

Explanation for change:http://www.religioustolerance.org/sabbath.htm

Catholic Catechism excerpts: http://www.biblestudy.org/godsrest/catholic-protestant-confe... The site is definitely biased, but it has a nice collection of excepts from christian and catholic doctrines.