How about this? It is taken from the Lutheran Witness, the official LCMS publication, and the article is written by the president of the LCMS. This is only the first part of the article.
The LCMS’s classic statement on creation was made a long time ago in the Brief Statement of the Doctrinal Position of the Missouri Synod (1932), and it still holds today:
We teach that God has created heaven and earth, and that in the manner and in the space of time recorded in the Holy Scriptures, especially Gen. 1 and 2, namely, by His almighty creative word, and in six days. We reject every doctrine which denies or limits the work of creation as taught in Scripture. In our days it is denied or limited by those who assert, ostensibly in deference to science, that the world came into existence through a process of evolution; that is, that it has, in immense periods of time, developed more or less of itself. Since no man was present when it pleased God to create the world, we must look for a reliable account of creation to God’s own record, found in God’s own book, the Bible. We accept God’s own record with full confidence and confess with Luther’s Catechism: “I believe that God has made me and all creatures.”
Over the centuries, there have been a plethora of attempts to alleviate the “scandal” of the creation accounts and to understand them in a way that is less offensive to human reason. Although it is true that the Synod has not defined as biblical doctrine a specific age of the earth, attempts to alleviate the scandal of the creation accounts by suggesting that the earth is somehow millions or billions of years old actually compound the scandal in my view. Can we somehow stretch the meaning of a “day” in Genesis 1 into an eon or long period of time? If so, then how is it that light is created prior to the sun? How is it that vegetation is created before the sun? How is it that God creates fish and birds prior to the other animals?
As I read it, he is saying that the church rejects atheistic evolution but not evolution itself and does not demand that it be six days as we normally count days. But the author then says that, in his own view, that alternative cannot be millions or billions of years if it's not the six day week. In short, there's the LCMS official statement, but his personal belief then fills in some of the explanation that was left open (and you'd be free to look at that matter differently). In other words, Josiah seems proven correct when he addressed what you'd really need to believe in order to be a sincere and loyal church member, and that's also what I suspect that the pastor you talked with was trying to get across.
