"There the angel of the LORD appeared to him in flames of fire from within a bush. Moses saw that though the bush was on fire it did not burn up."
The preach at reach the other night about Moses. While the main thrust of the message was about him being available, what resonated with me the most was the reference to this particular part of the story - the burning bush. (apologies for the picture - I thought it mildly amusing...)
The passage quite clearly says that although the bus was on fire it did not burn up - i.e. there was something else fuelling the fire: God. Had it been the bush that was fuelling the fire then eventually it would have burned out and the fire would have been extinguished.
This is a really useful picture for Christian life. If what I, as a Christian, use to fuel my 'fire' is myself - my good intentions, my own effort etc etc - then at some point sooner or later that fuel is going to run out. But if I let God fuel my 'fire', through the Holy Spirit, then it won't and I will be able to burn (in the spiritual sense!) without being consumed. Now there are a lot of cheesy Christian clichés in there but I think it's a really simple, yet really important, thing to keep in check.