Karen and I had an interesting discussion concerning the sinfulness of our thoughts. She postulates that we cannot control the thoughts that pop into our heads, as far as the "popping" goes. However, we can control what we do with the thoughts. For example, the following angry sentiment might pass through my mind: "Oh my gosh, I just want to go over there and hit Megan on the head" (which I really, really don't, because she's awesome). That would be one thing. If I got up and acted on that impulse--whack!--that would be another entirely.
Check out this verse:
For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin. (Hebrew 4:15)
Jesus was tempted in every respect. He couldn't have been tempted unless the corresponding tempting idea actually came into his mind, right?
It's very encouraging to think that he remained perfect in it all -- the utterly spotless sacrificial lamb. Now that the Holy Spirit indwells us as Christians, we are likewise released from slavery to our thoughts!
No temptation has overtaken you that is not common to man. God is faithful, and he will not let you be tempted beyond your ability, but with the temptation he will also provide the way of escape, that you may be able to endure it. (1 Corinthians 10:13)
We destroy arguments and every lofty opinion raised against the knowledge of God, and take every thought captive to obey Christ... (2 Corinthians 10:5)
All that to say, expectations, particularly unfulfilled ones, give rise to emotions that lead to unwanted thoughts in our brains. Those expectations are undergirded by deeply-buried beliefs, and any time we operate out of a flawed belief system, our emotions seem appropriate to the situation. Whether or not they are is not the point. The important thing is our decision about what to do with beliefs, emotions and thoughts.
Giving our expectations over to God says, "God, I am hurt. I am angry. I don't feel as if he's treating me lovingly (or understandingly, or fill-in-the-blank). Despite this, I choose to lean on the truth of your Word (for example, that I am eternally loved, even if people aren't "proving" that to me) and release this person from the responsibility to make me feel loved" (understood, etc.).
I type this with ease now, but I know that sometime today, something won't go the way I want it to. Welcome to life, right? When it does, I hope I take my emotion-born thoughts captive to obey Christ. It's good to know he loves me unconditionally even when I don't obey, and rejoices with me when I do.