Lectionaries are good things. In general they ensure that the worshipping congregation gets a good exposure to a broad range of scripture.
But (leaving aside the ancient lectionaries – which have their own peculiar histories of development) modern lectionaries are all products of editorial committees. These committees take liberties which publishers of the bible are not able to take: they produce lectionaries that are in fact “expurgated versions” – defined as much by what they leave out as what they include.
There is a clear example of this last Sunday (Catholic 4th Sunday in Ordinary Time / Lutheran 4th Sunday after Epiphany).
I went to mass in my local parish (as is my want) and heard 1 Cor 7:32-35, in which St Paul points out the fitting nature of celibacy for those who devote themselves to “the Lord’s affairs”.
Straight after this I went with my family to the Lutheran service, where they use the Revised Common Lectionary. The second reading set down in that reading is 1 Cor 8:1-13, about eating food offered to idols.
Neither text appears in the other lectionary.
The Revised Common Lectionary is, as its name suggest, a revision of the Catholic three-year lectionary. This would suggest that the Protestant editorial committee balked at having a reading which would suggest scriptural support for anything as “Catholic” as celibacy, and so opted for another text which (I would guess) the Catholic editorial committee decided was too complicated for ordinary Catholics to understand.
Neither lectionary is without its faults. Each one has the fingerprints of the ideology of their editorial committee all over them.
The traditional western lectionary isn’t perfect either, although at least it wasn’t put together by a committee!