The gospel lesson today is the story of Jesus and the disciples being criticized for violating Jewish Sabbath laws. This is a great text to begin the season after Pentecost, when we explore what it means to be the Church
Jewish Sabbath law is defined and governed by Deuteronomy 5:13-15. If you read this text carefully, you see that the practice of Sabbath (i.e. rest on the Sabbath day), has as its underlying purpose a remembrance of God's creation. But we also see that Israel is asked to extend rest to the foreigner and the slave, based upon the fact that Israel was formerly slaves and foreigners in Egypt, brought out of Egypt through God's grace.
By the time of Christ, Sabbath observance had become an extremely complicated practice. And yet all of the complexity arose out of defining what was and was not "work," and where "work" ended and "rest" began. Whether you could, for example, rescue one of your livestock on the Sabbath. Sabbath was not extended to the foreigner and the slave, and there was virtually no discussion about how to extend Sabbath to these populations.
Israel mirrored other cultures in having complicated rituals, like Sabbath. What made Israel different and set apart was the identification with the servant and the foreigner. By making Sabbath observance complicated and ignoring the question of how to show grace to the foreigner and the slave, Israel was defeating the underlying purposes of Sabbath observance
American Christianity makes the same mistake. Human culture emphasizes materialism, xenophobia, and self-interest. American Christianity seeks to turn the gospel into another mechanism to seek these things. Like Israel, the Church has been called away from human culture to live in a new kingdom defined by grace and redemption. Like Israel, the Church ignores the very teachings of Jesus that define it.