Fasting
What's with fasting? I know the standard flesh down - spirit up story and can (to a degree) buy into the simplicity of feed the white dog - starve the black dog, but my logical bit stays "why?" and "how does it really work?".

What is really interesting is that fasting is sometimes easier than others. I seems (subjectively to me, at any rate) that things I really care about are much easier to fast for than things that matter but are, well, a little more remote.
For example, a three day fast for peace in Zimbabwe is a tough one. As a friend said at the time, his mouse-mat looked like it just needed some tomato sauce and it was ready to eat.
An issue worth praying for? Quite definitely.
An issue worth self-sacrifice? You bet.
But an issue personally affecting me deeply as an individual - not too much. Most of the Zim problems are, as seen from my perspective, thankfully either second hand (I have a friend who has been forced to ....) or theoretical (New developments mean that maybe there will be a problem with ...).

On the other hand, when it is an issue which is to do with my own life direction - this is me now, not just the country I love and live in. Three days breezed past. Still enjoyed breaking fast at Adrienne's mind you. But why was I so much less skraal in this instance?
Could it be that flesh is down easier when I'm personally involved? That doesn't make sense. It's me therefore I'd expect flesh to be way up there.
Could it be that me issues are less important than national issues, so Satan doesn't tweak the gut as badly? I doubt this too. An individual in God's will must make an impact on the nation as well, so He should be extra cautious when Christians seek to be in the right pace at the right time.

I suspect it is something more sinister that this. Too often, I seek God's direction, say "Thanks, God", and then do my own thing again. Maybe this is human nature, but it's my nature as well. Satan is well pleased to let me feel good about seeking God - so long as I don't do anything about it.
C.S.Lewis says something similar in The Screwtape Letters. Screwtape (the Senior Devil) writes to his underling, Wormwood, and points out the advantages of distracting "the patient" from the promptings of God just long enough for them to fade into unreality. In the first letter he says "I once had a patient, a sound atheist, who used to read in the British Museum. One day, as he sat reading, I saw a train of thought in his mind beginning to go the wrong way. The Enemy, of course, was at his elbow in a moment. Before I knew where I was I saw my twenty years' work beginning to totter. If I had lost my head and begun to attempt a defence by argument I should have been undone. But I was not such a fool. I struck instantly at the part of the man which I had best under my control and suggested that it was just about time he had some lunch. The Enemy presumably made the counter-suggestion (you know how one can never quite overhear What He says to them?) that this was more important than lunch. At least I think that must have been His line for when I said "Quite. In fact much too important to tackle it the end of a morning", the patient brightened up considerably; and by the time I had added "Much better come back after lunch and go into it with a fresh mind", he was already half way to the door. Once he was in the street the battle was won. I showed him a newsboy shouting the midday paper, and a No. 73 bus going past, and before he reached the bottom of the steps I had got into him an unalterable conviction that, whatever odd ideas might come into a man's head when he was shut up alone with his books, a healthy dose of "real life" (by which he meant the bus and the newsboy) was enough to show him that all "that sort of thing" just couldn't be true."

The challenge therefore of a time of closeness with God - be it fasting or otherwise - is to carry the "God-ness" into action. This is a start. Then comes the next challenge of doing it when we are not feeling as close to God. As Screwtape says in the eighth letter, hell's "cause is never more in danger, than when a human, no longer desiring, but still intending, to do our Enemy’s will, looks round upon a universe from which every trace of Him seems to have vanished, and asks why he has been forsaken, and still obeys."