Sabbath Keeping

Our Sunday school class is looking at what the PCA, my denomination, believes on certain issues.  The last several weeks has been on worship.  Today, we were ending the worship discussion and the homework that we were to read included a section of the Westminster Confession of Faith (scroll down to pages 19 & 20) and it's statements about the Sabbath or Sunday and what is expected.  The last part of the section on "Religious Worship and the Sabbath Day" says this:

viii. This Sabbath is then kept holy unto the Lord, when men, after a due preparing of their hearts, and ordering of their common affairs beforehand, do not only observe an holy rest, all the day, from their own works, words, and thoughts about their worldly employments and recreations;(1) but also are taken up, the whole time, in the public and private exercises of His worship, and in the duties of necessity and mercy.(2)



(1) Ex 20:8; Ex 16:23,25,26,29,30; Ex 31:15; Ne 13:15-19,21,22.


(2) Isa 58:13; Mt 12:1-13.
 
Now, I don't know if we ran out of time, which happens a great deal, but we never got here.  Our family does  not keep the Sabbath perfectly--not even close--but I would love someone to make a stand about this!!  Does God change his mind?  What about the way He talks about the keeping of the Sabbath in the Old Testament?  I think He is serious.  Sunday has become another Saturday.  Our culture has lost any concept of what this day really means and the reason God commanded it.  Many think that if they have attended church service, they are done--card is punched.  We can do whatever we want. 
 
Of course, I am old enough to remember the days when the stores were all closed on Sunday, except for the drug store for a few hours.  It was a great scandal when our local corner store opened at noon for people to get the Sunday paper.  My dad told me that they were only permitted to read the Bible or nap on Sundays when he was a boy.  They were not even permitted to read the Sunday comic strip.  How far we have come.
 
I just want to know if God has changed or if our culture has perverted this day so badly that it seems that it cannot be redeemed.
 
If God commanded a day of rest, he has good reasons.  We work against this perfect plan when we disobey. Will there be some sort of judgement on our nation, or on us personally?  I don't really know. 
 
I want to understand how to do Sunday in an obedient way.  Please tell me how!!

No doubt, I need to start with blogging on Sunday.  This was something I had to get off my chest.
 
O LORD,
We commune with thee every day,
   but week days are worldly days,
   and secular concerns reduce heavenly impressions.
We bless the therefore for the day sacred to our souls
   when we can wait upon thee and be refreshed...
--an excerpt from Worship from the Valley of Vision