And Jesus was driven into the desert by the Holy Spirit to be tempted ...
Why the desert? Why to be tempted? Why by the Holy Spirit?
Let's think about the desert. What are some things in the desert that we can't find in normal everyday, urban existence?
First, the desert is a place of isolation. No one's around. Nobody peeking over your shoulder to see if you're behaving like a Christian. Inconspicuous. Christendom is a long way away. Here, no one knows about your vows, your convictions, and no one expects you to uphold them and no one cares if you do or don't. You could sin, and no one would know, in fact, it was most "normal" of you to do so.
Second, the desert is where you're at the mercy of the environment. The sun will beat on you during the day, the frost will bite you at night. Sand storms, venomous critters, hungry animals. It's where you need to keep alert and deliberately work at surviving. The only time you "get used to" that environment is when you're dying - reaching homeostasis with the surroundings, they say.
Third, in the desert is a lack of sustenance. No abundance of the usual things we feast on so gluttonously. No conferences, seminars, commentaries, 5 different versions of Bibles. Just you and whatever comes out of the mouth of God, and the mouth of the raven. Maybe there isn't a lot of new insights, but a time when you get to think long and hard about the stuff you've already learned. Now is the time to make sense of it all, ask yourself if you really believe it - out here, like you thought you did back there.
When God tests a man in the desert, it's not to see how he'll do. He's not ignorant of the future or our prospects for success. It's not so that God'll know how we'll fare. It's so that we'll know. It's for us to find out what God really means to us. It's for us to see what we're made of; whether we revert to our animal instincts, or we abide in the Spirit. It was essential for Jesus' ministry to find Himself in God and experience Him in the desert, away from everyone, away from the expectations of being the Son of God. The testing was about His humanity and the place that God occupied in the heart of a Disciple. The wilderness is where we each need to go and meet God ... at some point.