In Jeremiah 31:40, the prophet says that the city of Jerusalem would be rebuilt and never again destroyed. The context is the new covenant, so is it referring to the church instead of the city, since the temple was destroyed again in 70 AD? -- James Shults (Oklahoma City)

Good question! I think Jeremiah is referring to the time of Nehemiah, the time of the return from exile, and only secondarily to the time of the church. 

Some of God's promises read unconditionally, yet may be invalidated by human faithlessness. See Jeremiah 18:7-9: "If at any time I announce that a nation or kingdom is to be uprooted, torn down and destroyed, and if that nation I warned repents of its evil, then I will relent and not inflict on it the disaster I had planned. And if at another time I announce that a nation or kingdom is to be built up and planted, and if it does evil in my sight and does not obey me, then I will reconsider the good I had intended to do for it."

Let's consider another passage. Leviticus 16:33 says that wherever they live, on Yom Kippur the Jews are to make atonement for the Holy of Holies. This is a "lasting ordinance." And yet this is obviously no longer possible! In other words, some things in the Bible are written in absolute terms, as immutable decrees or promises, and yet they are not. In the words of the great Jewish theological Abraham Joshua Heschel,

"God is compassion, not compromise; justice, though not inclemency. The prophets' predictions can always be proved wrong by a change in man's conduct, but never the certainty that God is full of compassion" (The Prophets, p.16. ISBN 1-56563-450-0).