God changes his mind?

Here's an example of on of the many things I don't understand:

In those days Hezekiah became ill and was at the point of death. The prophet Isaiah son of Amoz went to him and said, "This is what the LORD says: Put your house in order, because you are going to die; you will not recover."

Hezekiah turned his face to the wall and prayed to the LORD, "Remember, O LORD, how I have walked before you faithfully and with wholehearted devotion and have done what is good in your eyes." And Hezekiah wept bitterly.

Before Isaiah had left the middle court, the word of the LORD came to him: "Go back and tell Hezekiah, the leader of my people, 'This is what the LORD, the God of your father David, says: I have heard your prayer and seen your tears; I will heal you. On the third day from now you will go up to the temple of the LORD. I will add fifteen years to your life. And I will deliver you and this city from the hand of the king of Assyria. I will defend this city for my sake and for the sake of my servant David.' "
2 Kings 20:1-6

If God doesn't change, then why does he change his mind? Why would God chnage things because of people praying?
Maybe he intended to change his mind all along once Hezekiah had humbled himself. But if YHWH was intending to heal him all along he would have been lying to say that Hezekiah wouldn't get better.
Another idea that came to mind is, maybe God really did intend to let Hezekaih die, but was emotionally moved by Hezekiah's misery, to the point that he was willing to change his plans, even though he was in the place of authority.

Hezekiah

In the fourteenth year of King Hezekiah's reign, King Sennacherib of Assyria came to attack the fortified cities of Judah and conquered them. King Hezekiah sent this message to the king of Assyria at Lachish: "I have done wrong. I will pay whatever tribute money you demand if you will only go away." The king of Assyria then demanded a settlement of more than eleven tons of silver and about one ton of gold. To gather this amount, King Hezekiah used all the silver stored in the Temple of the LORD and in the palace treasury. Hezekiah even stripped the gold from the doors of the LORD's Temple and from the doorposts he had overlaid with gold, and he gave it all to the Assyrian king.
2 Kings 18:13-16

I was really surprised when I read this bit. I was pretty sure Hezekiah was one of the kings that honored YHWH, and for some reason I thought YHWH wouldn't be to happy with him giving away all the Temple's silver. But it doesn't say anything about God getting angry about it, and he looked after Jerusalem all through his reign.

Stealth idols

When the Israelites were wandering in the desert, and were attacked by snakes, YHWH got Moses to make a bronze snake. Everyone who looked at it was cured of snakebite. (Numbers 21:4-8)
However, the Israelites eventually ended up worshipping the bronze snake, and King Hezekiah had to destroy it. (2 Kings 18:1-4)

It seems as though a gift or tool can become an idol, even though it's good and God has given it to us. We can end up putting our faith in these things, instead of in God, who gives them to us.
It's possible for us to idolise buildings, music, scripture, particular forms of church. In the emerging church we're just as much at risk of this. We're just as susceptible to idolising postmodernity as our predecessors were to modernity. Any ideas about how we can avoid this?

Sell-out

I've decided to start blogging stuff that stands out to me when I read scripture, to make sure that I am taking something in. So if I don't say much about what I've been finding in the scriptures, please email me and ask, because the chances are that I haven't been bothering.

Just read 2 Kings 16. I was pretty upset that the Israelites' exile started because King Ahaz let King Tillegath-pilneser of Assyria take over Damascus, in exchange for protection from Prince Pekah.
In the next chapter, Tillegath-pilneser's successor, Shalmaneser took over Samaria, so King Hoshea (Pekah's successor) asked the King of Egypt for help.
The people also tried to solve their problems by worshipping idols, through magic and by ignoring YHWH. As a result, the Israelites (except for Judah) were exiled to Assyria, and their land was resettled.
I suppose what I understand from that is that we need to depend on God before we depend on other people or on money or strategies or whatever.

Another thing I noticed was that the new settlers were given an opportunity to follow YHWH:

The king of Assyria then commanded, "Send one of the exiled priests from Samaria back to Israel. Let him teach the new residents the religious customs of the God of the land." So one of the priests who had been exiled from Samaria returned to Bethel and taught the new residents how to worship the LORD.
2 Kings 17:27-28.