A Question For My Christian Friends (and everyone else who wishes to reply)

First:
When did Sunday Replace the Sabbath?

In 364 CE!

As the Catechism of Catholic Doctrine says on page 50 (3rd edition):

Question: Which is the Sabbath day?
Answer: Saturday is the Sabbath day.
Question: Why do we observe Sunday instead of Saturday?
Answer: We observe Sunday instead of Saturday because the Catholic Church, in the Council of Laodecea (A.D. 364), transferred the solemnity from Saturday to Sunday.

So Here's My Question:

Where does God's word tell Christians to adopt Sunday and cease honoring the Fourth Commandment, Genesis 2:3 and scores of other verses about Shabbat?

And a Follow-up Question:

If the Bible does not teach that Sunday is the Holy Day and does not teach that Shabbat has been negated...

Then... Should Christians obey Rome or God?