The way that I understand it is this: We are not under the 10 Commandments because the 10 Commandments were given to Israel alone. The Sabbath especially was a sign between God and Israel, Exodus 31:12-17.

Gentiles, generally, were never bound to the Sabbath or the Law. Today Gentile Christians are under the New Covenant, that is:

1 John 3:23 And this is his commandment, That we should believe on the name of his Son Jesus Christ, and love one another, as he gave us commandment.

This is from a gentile point of view. It's pretty simple once you see it.